what do you do or say when someone doubts you online?

Question

before, someone replied to my comment on youtube where i declared the fact that i am of spanish descent & im a man in my 40s from Britain....and the man who responded said ' you are not of spanish descent'.......and i felt in disbelief and at a loss, slightly annoyed too....i haven't replied to his comment yet.....but i wonder what do i do or say to someone online doubting facts i declare about myself?

Update:

drip- i felt the need to declare it because it was on a video about spain by an english uploader, and i got offended because i'm quite touchy. 

Answer 1

Favorite Answer

Why would you even mention you are of Spanish descent? 

Why do you care some stranger doesn’t believe you?

Answer 2

i probably wouldnt bother replying

Answer 3

Why do you feel the need to respond?  Forget about it and move on.

Answer 4

I remember the sole purpose of trolls, is to irritate their betters.