Stimulants make your brain go brrr. I know they increase dopamine levels and so on, but I have no idea how that translates into personality. I think a friend coined the term talking about SBF. I also know they can cause mania in people with BPD.

From personal experience, they make you feel like you're on top of the world. You can get so much done. Although obviously in some people they just help you focus a normal amount.