Assume, that the universe had a plan, which consisted of the father getting freaked out on the night, not getting any action, and ultimately end up being admitted to a mental home:
So, in order for this plan to come to fruition, his Son would have to exist, to go back in time and freak out his future father. Otherwise, the soon-to-be father would have not gotten freaked out because there would have been no future Son tapping him on the shoulder.
And the only way that the universe can create the enviroment for the father to get freaked out, is for a Son to be born, with much self-hate, etc. that makes him go back in time to cancel his own creation, so to an observer, it seems that the father lost his mojo, went to sleep, and had his first meal in a mental home soon after.
Im after confusing myself there