You are 21 and many feel unsure at that age. You are not alone. You seem to already have social skills. Continue to network and exercise your social skills. And read those social books too, to find where improvements can be made. Will someone mock you? I would say that 90% will not (***in every group of 10 you likely can gain 9 allies, and that's good odds***). There will be some who will. Some of these toxic people do not realize that they are idiots until someone tells them so. So do react if it happens. Or at least stare at them. Yes, the stare can sometimes cause them to realize that it's not all a joke: There have been a few who have apologized. Find many ways to troubleshoot that problem.. And keep in mind that it only last a minute, then it's over, and you respond and tell them it's "stupid behavior." You may even show them that many celebrities stutters: The celebrity printout works with adults too. Find other ways to trouble shoot the situation. Sometimes you just have to tell the person to stand outside until you are done, if they can not control themselves: That gives others a clue or two, and they too would tell them to leave if they do not improve. Those embarrassing moments in life do not last but a moment. You can repair that. And sometimes those people around will not be scene again. Keep your friends close. They will enjoy you standing up to the bully, and will help. Everything is a journey.