I started off being a bit cagey on here & sometimes posted a couple of red herrings in case anyone in RL spotted me whingeing about my family etc.
I still namechange quite a lot because I cannot resist telling friends about MN and practically pressgang them into having a look. I then have paranoid episodes where I imagine them discovering who I am and searching my posts... then cringe at what I've written about ladybits or whatever and imagine them telling their DHs...then cringe at myself for being so self-important to think that anyone would ever do that...
So yes, I sometimes tell the odd fib. Not for delusions of grandeur reasons, just for preserving anonymity.