Yeah, speaking as someone who teaches at university, there is nothing more irritating than when an older mature student sits in my seminars and tries to patronise and undermine me. No asshole, I'm the one who has spent years of my life becoming the academic, you are not an expert in shit just because you've lived longer and have issues being taught by someone younger than you.

Thankfully, it's rare. I've only had it twice and once it got so bad (and combined with a healthy dose of misogyny and sexism too) that I actually had to have him removed from the course because it was so disruptive. Most mature students are awesome though.

The only other piece of advice I would give, and this may only be relevant to humanities subjects, is don't mistake your life experience for evidence. I taught a woman who would constantly in seminars bring up how her experience of living in the Dominican Republic for a year didn't match up to what we were talking about regarding US-Caribbean relations. That's nice, her experiences were interesting and I would have loved to have heard them over a drink, but they are anecdotes and were not not meaningful or relevant in the context of what was being discussed. Same kind of applies to industry experience. We love it, it's useful to us as academics, but it isn't always relevant to the theories or broader themes being discussed in an undergraduate seminar.