Not relating to Dr Doireann but of course you can be an expert in something at 33. Finish school, do your degree and be in a workforce for 10 years by that age with upskilling along the way. You don’t even need a degree or to have finished school, anyone with a work ethic, drive and ambition in their late teens can be an expert in a field 15 years later at age 33.
I understand where you're coming from, but I respectfully disagree. For me, an expert is someone with at least a couple of decades of real life and professional experience.
If I was attending a Doctor, and they were calling themselves/purporting to be an expert at 33, I'd be seriously questioning how they were representing themselves. And why. Just keep working. Genuinely gain your expertise. Why the need to be so performative?
Just to be clear, I totally respect anyone in any field who works hard and learns. Earns their stripes. Carpenter, doctor, plumber, whatever. I've an uncle who is a successful builder and so was my grandad. They would never have presented themselves as experts in their early thirties.
And sorry, I don't want to derail this thread or get into it with anyone!