The first time I took creatine (6g IIRC), I actually felt the mental effect just 2 minutes later. A pleasurable sensation of augmented presence and (mental) relaxation.
I paused taking that momentarily out of precaution while I wait some physical issue to normalize, but I plan to resume it in some weeks. Also it is considered a very safe supplement.
How can you be sure you weren't placebo'ing yourself into feeling it?
To my knowledge creatine has no significant effects until your levels rise after, say, a week of taking daily
Did you inject or smoke it in order to feel "the mental effect just 2 minutes later"? Taken orally it can only be placebo effect.