The Expert Illusion: Building Confidence Across Disciplines

Being cross-disciplinary is a gift but it can also trigger a deep identity crisis. Am I a physicist? A biologist? An image analyst? An expert… in what, exactly?
Here I dive into what I think it really means to be an expert when you work between fields, and how I’ve learned to stop apologising for it.
If you’ve ever felt like you don’t quite fit, this one’s for you.

Hi there! I’m back.
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These past few months have been wild. Back-to-back conferences, talks, panels, seminars... moments in the spotlight that leave you a little breathless. If you know me, you know that public speaking doesn’t come naturally to me. Not because I don’t like to talk, I do, but because deep down I still struggle to believe I’m the right person to be speaking at all. I still struggle to believe I’m ‘the expert’.

So when people come up to me after a talk and say, “You’re so confident!” or “I wish I could speak like you,” I want to take them by the hand and whisper the truth: What you’re seeing isn’t confidence. It’s scaffolding, something I build brick by brick, every single time. Because the hardest part of being cross-disciplinary isn’t the learning curve. It’s the identity crisis.

I know I’m not the only one feeling this way, so today I want to take you behind the scenes of that scaffolding. I want to share some of the strategies I’ve learned to feel more like an expert; how to recognise my value in context, stop undermining myself, and learn to present my expertise with confidence.

​Living in the In-Between

​Let me rewind. I started out as a physicist. A proper, hard-core, chalk-dusted theoretical physicist. I could model the hell out of a universe. But somewhere along the way, life nudged me down a path I didn’t expect...into biology. Cancer research, to be precise. That shift was not just a career move, it was a seismic shift in identity.

Today, I live in the space between physics, computational science, and immuno-oncology. I’m a cross-disciplinary scientist, which means I’m always learning, always translating, always negotiating between worlds.
And that’s beautiful. And brutal.

Because when you’re working across disciplines, you often feel like you belong fully to none. I’m no longer proving theorems or inventing new physics. So part of me thinks: I’m not a "real" physicist anymore. And I’m certainly not classically trained in biology. I know the narrow slice I work on, yes, but not everything else. So part of me thinks: I’m not a "real" biologist.

And here’s where it gets dangerous: just like that, I’m standing in a room full of specialists: physicists, computational biologists, immunologists, and I assume they all know better than me.
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Turns out, this feeling isn’t rare. It’s epidemic among cross-disciplinary researchers. Especially women. Especially those of us who grew up being praised for being "hard-working" more than for being "brilliant."

​Redefining Expertise

One day I met Julia. She’s my mentor in the Women of Influence programme, a mentoring scheme that pairs researchers with top UK businesswomen, offering support and guidance from outside academia. Julia is a powerhouse of a woman: the Global Head of Coaching at one of the most prestigious law firms in the world. Not an academic. Not a scientist. Just incredibly wise.

One day, in a conversation about expertise and credibility, I said something like, “Well, I’m not an expert in biology…”
She stopped me. And then she asked, “What does it mean to be an expert in biology?”

It sounds like such a small question. But I swear, it cracked the floor open under me.
Because really, what is an expert?

Biology is huge. No one knows all of it. Just like no physicist knows every subfield of physics. Just like no coder knows every language. Most people are deeply specialised in a narrow corner of their domain. They say, "I study autophagy in breast cancer," not, "I know biology."
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So I thought… what’s my narrow corner? And I realised: I understand immuno-oncology better than many classically trained biologists. I’ve taken dozens of courses — online, in person, in labs — to learn what I needed to learn. I know how to build physical and computational frameworks to study these biological processes.
That is expertise.
That is mine.

​From Undermining to Owning It

But here’s the trap: I didn’t always present myself that way.

In biological conferences, I used to introduce myself by saying, “Hi, I’m Luciana — I’m a physicist, so please bear with my biology.” Or, “I’m not really an expert in this, I’m just trying to help.”

I thought I was being honest. I thought I was building trust by lowering the bar. But in reality? I was undermining myself before the conversation even began.

Julia spotted this in me immediately. She said, “Move away from the generics. Don’t say what you’re not. Say what you do. Be specific. Be contextual. Be smart about it."

She was right. I know it because I saw it in action.

At a microscopy conference, one of my favourite people/scientists in the whole world — Maddy Parsons — introduced me to someone by saying: “This is Lu. She’s a super-duper image analyst.” And something clicked. That was exactly what I was in that moment. Not a physicist. Not a biologist. A damn good image analyst. And suddenly, people leaned in. They listened. They asked questions.

Maddy knows I’m a physicist. She knows my journey. But in that room, in that moment, the relevant truth was: I analyse high-plex images, with a particular focus on immuno-oncology. That’s my expertise. And that’s what people needed to hear.

It's not enough to know what’s my narrow corner, I also need to know what's relevant in the context.​  So now, before I introduce myself, I ask:

• What is my expertise in this room?
• What do I do here that makes me valuable?

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​It’s all about focusing the lens.

​Reinforcing the Scaffolding

Yes, knowing my expertise is key, but it's not enough. Here are a few shifts that helped me reinforce that scaffolding. Small, practical things that changed the way I carried myself.

You don’t need to apologise for not knowing everything. Even the most seasoned experts say, “Sorry, I’m not familiar with that, can you explain?” It doesn’t make them look weak. It makes them look interested. Curious. Capable of learning.

Accept praise. When someone came up to me after a talk and said, “Luciana, that was brilliant,” I used to say something like, “Oh gosh, really? I was actually very nervous.” (accompanied by an awkward, I-want-to-disappear smile). Not exactly expert energy, right?

Now I try to say something like: “Thank you. Do you work on something similar?” 

Praise, received. Connection, built. Doors, opened.

Don’t deflect. When someone called me brilliant in a room full of people, I used to deflect, say they were being overly kind. That’s not humility. That’s self-sabotage. By saying that, I wasn’t just putting myself down, I was also questioning the other person’s credibility.

Now I simply smile and say: “Thank you.”

Small things that make a huge difference.

​The Takeaway

There’s a reason we look to experts. They give us something to lean on. Not because they know everything — but because they sound like they know what matters. And in science, that kind of presence is powerful. It opens doors. It secures funding. It gives patients hope.

Well, good news: we are all experts, just in different things. Expertise isn’t about knowing everything. It’s about knowing your thing. It’s about showing up prepared, curious, and open. It’s about standing tall in the weird little intersection you’ve carved out for yourself.

We can be experts in multiple things. Learning to identify your expertise in a way that fits the context is what helps you feel like an expert and look like one too.

Don’t put yourself down for not knowing everything. It’s OK not to know. Imagine how boring life would be if we did.

So yes: fake it till you make it. Confidence isn’t built in a day. But these small shifts, these little reframings, helped me more than I ever expected.

If any of this resonates with you, and you want to talk about it or share your story, get in touch. And if you have tips of your own for reinforcing the scaffolding, I’d love to hear them. :)