If I go back to a year that's after my birth, what happens to me? Do I coexist with a younger copy of myself? Does that copy suddenly get erased the moment I join? Or do I simply move to a timeline where I had never existed in the first place?
Your copy is erased.
Well that's scary, I don't want to find my parents mourning the sudden inexplicable disappearance of their son or something like that.
And if I go farther back in time, this probably means that when I reach 2000 I never get conceived, which is just too weird and paradoxical. Given my current age, even if I choose the earliest date possible of 1951, I am pretty likely to reach that year alive. So I am going to vote NOTA, I'd stay in 2021.