I had one girl (maybe in her 20's, not a kid) the other day come in and looked in each and every SW tank I had, asking for every single fish "What's that?" "Pipefish" "What's that?" "Damsel...". After a few of those I explained about the tags having the names of the fish on them... so then she proceeds to ask "What's a Yellow Tang?" "What's a Dragon Wrasse?"...it was just very awkward. Oooh, and then she's looking at my feeder guppies, and proceeds to tell me one's pregnant and I need to take it out now so it can have it's babies in peace. (Despite the fact that all of them are probably pregnant)..I kind of say yeah yeah I will get to it, to shoo her off, and she's like NO she's going to have babies any second! Put her in another tank! I literally did it just to appease her and make her go away....but no she had to stand there for half an hour watching it.
People also "hand pick" guppies out of the feeder tank...I honestly don't mind grabbing either females or males, or more pregnant ones, but when you want a specific one out of about 500 guppies...it's ridiculous. Same thing with the feeder goldfish, I had one lady practically yelling at me because she wanted goldfish with NO white on them, and one I got had a little white chin.