Until I was 27 I avoided all illegal drugs on the theory that they'd be like a random edit to my core self, after which I could no longer trust who I was. Eventually I decided both that there were parts of me so stable they were unlikely to be changed, and that there were other parts for which even random change wouldn't be so bad.

Not open to new experiences? I think I just read about something to cure that.

Snark for snark? If you trip out, do you think you'll become open to the new (I presume?) experience of raping the corpses of decapitated skin-tumor-ridden grandpas?

Hey, I like who I am too. But I know that I can be better.

I want to be better, too, and I'm continually working at becoming such. But I'm not convinced that tripping is a guaranteed way to betterness, nor how much better any accidental betterness would really be.

Nothing is a guarantee in life.

And not all probabilities are equal. I haven't implied there exists something which is a guarantee, I have stated that I don't think taking drugs is a guarantee to becoming better. Being more technical, taking drugs as an action for becoming better is heavily outweighed by other options in my expected utility function, both probabilistically and in amount of utility. (Of course this could change.)

I'm going to get better through work and understanding, not dumping random chemicals into my brain.

Presumptuous and scared? New experience changes you.