It's funny how drugs and alcohol affect people differently.
I'm probably the nicest person that you could be around when I'm high or drunk. I don't get into fights or do anything to harm others (accidental self-harm on the other hand...). I've never managed to destroy a relationship due to my substance use.
I've never woken up in the morning and had to worry if I've left a trail of destruction behind me. Sure I've done dumb shit, but it's never hurt anyone else.
I'm actually more of an arsehole while I'm sober. I'm a nicer and more agreeable person when high, which is its own problem that I've been working through.
Drugs bring out our most base traits. For some that's a good thing, for others it's not.