Strange as it sounds, I actually have a near-instant reaction to one specific anti-depressant. Multiple times in my life, I've gone from nothing to that and felt a change same-day. As a rule, I tell myself that I need to observe a change for three days in a row to not count it as placebo. At least three times that I can recall, on the third day I was like, this is definitely working.
Every other medication is like the meme, except for side effects.
I was on this too, and I didn't realize it at first, but I noticed I had almost immediately quit smoking, like overnight. I didn't know until months later that it's also used to treat depression but also to help people quit smoking. I came off of it after about a year and half and never felt the urge ever again to smoke.