My first experience with tech-diving made me realize I know crap all. Indeed, on one day of training, the scenario we were running stressed me out a lot - I did not know up from down I think - we were practicing solo ascents, having a surface marker deployed with a free flowing regulator and a flooded mask. I declined the second training dive of the day.
I was shore diving once and had some blowhard bleat about my gear, as if I somehow looked like I just started diving and needed his expertise about what type of wing I should have bought instead of the one I had.