Long story short : I went to my sisters gym with her today because she's starting a lifting routine and I wanted to show her proper form and how to do a bunch of exercises. Some guy who was walking around and cleaning glass (who didnt look / sound retarded to me .. asides from the advice he was offering ) started talking to us and trying to give us workout "pointers" that were completely wrong. I was showing my sister how to squat, box squat, and do deadlifts and the entire time this guy is saying things like "that's bad for your back." or "if you go that low you're going to blow out your knees.". I didn't feel like arguing with the guy but I wasn't going to stand for someone trying to throw misinformation at me (especially since I'm trying to teach my sister the proper way to do things) so I would just curtly tell him "no it's not." to which he would respond with things like "oh? well i've never seen anybody do them here." or "the biggest guys i've ever seen in here never does things like that." I finally got sick of it and just rudely said "listen man. you're not a personal trainer. and even if you were, I didnt ask your advice, so don't give it to me because it's wrong anyways. now please leave us alone so I can show her how to workout properly." and afterwards my sister goes "I can't believe you said that to him, he's semi-retarded." I felt really bad CLIFFS : went to my sisters gym, showing her how to deadlift and squat properly, semi-retarded worker keeps trying to give us stupid pointers, I flipped out on him. I didn't realize he was retarded. I felt bad.