I can never get a vasectomy, I just can’t say what will happen in the future. Suppose there’s’ some sort of societal collapse, man becomes an endangered species, and I somehow end up captured by a tribe of busty amazonian women who want to use me as a breeder, just constant and frequent encounters with different women every night. However, they check to see if I’m still fertile and realize I had a vasectomy, then they kill me and eat me. I can’t take that chance.