And if I wasn't high, I'd probably try to blow my brains out
I'm hopeless, they should've killed me as a baby
I think this is the correct view that Tupac takes. Theologically I am not sure if all babies go to heaven since we are all born in sin, Romans 5:12-21, but, I think you are right to accept this line as what Tupac believes.
he said they should have killed him as a baby because babies are innocent and are guaranteed to go to heaven and not have to live thru life he was always talking about heaven and he feels guilty for some of his actions and has regrets and it would have been easier if he would have not been born because suicide is a ticket to hell so during his life he ponders if he will go to heaven or hell
he smokes weed to get away from the reality that drives him crazy to the point of suicide.
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