Yep, very funny, we know. Nevertheless, it represents a good point in the swim, which is: Be prepared. There will be contact. But in many cases, the contact is incidental - not bone crushing. People will touch your leg or hit your arm. Or you might hit someone's leg or arm. In mass swim starts like Ironman, the contact likely will occur more often. In wave starts, thinner fields promote less contact, but watch out for the faster waves that come from behind.
Like you, most people are nervous about the swim. Therefore, when the gun sounds or the race director bellows that it's time to go, everyone sets off for the first buoy. When everyone gets there is when the trouble ensues. Not wanting to swim more than necessary, most people want to round the corner right at the buoy. The problem is that everyone gets caught up, like when traffic comes to a standstill during rush hour at every freeway entry ramp in the country. There is a solution: Stay to the outside. You may swim a little farther, but you won't get caught in the pack at every turn.