RE: The Most Difficult Philosophical Question I Can Think Of
In order for you to ever be born in the first place, someone had to impregnate your mother. If you didn't exist yet, there would be no you in the future to go back and impregnate your mother in the root timeline, which means that someone else had to have impregnated your mother. That means that you don't need to impregnate your mother and old you is probably a self-loathing jerk that's just messing with young you for some sadistic reason.
Also, genetically, you can't actually make yourself by having sex with anyone, that's not how it works. You'd only make a new person with similar but slightly different genes than what you have, not you. You'd be giving yourself a brother or sister that is also your son/daughter, not creating yourself.
If anything, going back in time and impregnating your mother severely reduces the probability that you actually get created in the first place. Since you cannot be your own father, you could impact the ability of your actual father to create the real you in the root timeline by adding the variable of another man (you) and another child.
So, I would take this as a warning that I have some mental issues when I get older and I would seek to change that future. :)
Right that's kind of a twist on the grandfather paradox. If you don't do it then you would not have gotten the message to do it in the first place. But maybe the old you is just trying to protect his own existence because some other you did the exact same thing to him. You bring up a good point about making new people. I think that time travel would trigger the butterfly effect and ultimately the world would change more radically than one might think. There would be a bunch of new people and allot of old people would probably not exist at all. Meaning the entire history of the future gets changed your family might not exist at all in the future even if you did do it. You make lots of interesting points.