One uppers and know-it-alls are are particularly annoying to to those of us who actually have done everything and truly do know everything.
One uppers come across as thinking they are better than you but in reality you need to be patient with them because they don't think they are better than you at all. In fact, they view you as someone who is higher up on the imaginary social ladder and who is worthy of impressing.
There's a guy at work like that, no matter what you say, if hasn't done it better himself, he knows someone who has .
Him: Oh, I never check luggage when I travel....it's strictly carry on for me.
I usually make some sort of joke out of what he's saying and once he sees I couldn't give two rat's asses about anything like that, he backs off.
Me: Me too, I usually stuff everything into a black garbage bag and drag it on the plane with me.