1. "I don't want to become huge and disgusting, so I'll stick to cardio." This is not going to happen, it takes many years of intense and intelligent training to gain significant size in body mass. All of sudden they have the secret gene to get huge and if they touch the weight and look like Ronnie Coleman, I don't F*ckin think so.....
2. "Do you think I am over training, full body workouts 4 time s a week is OK, huh?" Your body needs plenty of time to recover, and when working out at max intensity many body parts will need more than one day.....
3. "Why can't I gain any weight?" Since you cardio for an hour or burn more calories than you intake then this energy is taken from you body in either fat, muscle or Glucose from the liver. So to gain weight you need to eat more than you expend, hence needless exercises for an hour are not helping.....
4. "If I lift weights I will become rigid and stiff and will not be flexible any more, and I will not be fast to boot" Flexibility can be increased by stretching, just because you gain some muscle doesn't mean you can't be flexible, if you train to get stronger you can train to get more flexible... Speed can also be trained for as well, Olympic lifters are some of the fastest people on earth and almost all olympic sprinters lift weights as well, to get speed, train for speed.....
5. "Look over there he's gotta be a juicer cause I have been lifting for a year and he can do more than me and he is younger." Not everyone juices and just because they can lift a lot doesn't mean they juice, sometimes there are people who just work hard, and age doesn't always bring experience, results and errors and success does...

These are some of the myths that piss me off to no end because they are based on ignorance, that is why they are myths, meaning they are just stories people tell.