I have mixed cichlids and oddballs. When buying fish, I often find myself pointing at one specific fish and sticking with it no matter how hard it is for the poor sale person to catch.
The reasons behind this is: -
1) You are paying for the fish and have a right to select which one, however I purely talk about the type of fish I have, not small little ones.
2) I carefully watch the fish first to see which ones are aggressive etc and wait until I find one that seems peaceful
3) You may see one with more colours in it and/or has more of a colour in it which you like.
So yes, I am sadly one of those annoying people that specifically points and shouts, 'I want that one pweassse'.