The point of no return theory is when you take a member of the opposite sex (usually female) home to have sexual relations/fellatio. As you take off your clothing, she realizes that you have a tiny penis and/or a beer belly, but since you have already gotten to this point she might as well hook up with you--hence the point of no return. Essentially, a common bond amongst the ugly people of America where hope is found.

when you've done something so cringe you can't stop replaying it in your head and it stops you from getting on with your every day life