I bet you didn't really forget that Lexapro. Same way I seem to "forget" my Zoloft at the start of a meth binge.
SSRIs have a certain kind of drug interaction with meth. Not one that's bad your health, just one that's not as conducive to some of the more common hobbies associated with guys on meth.
You probably didn't realize that yet, though, so, fair enough.
Anyway, if you enjoy your healthy living, a meth habit will drive you nuts. Meth doesn't make you hate water, or anything. Water bottle's right next to me, cause I know meth makes your kidneys suck every last drop of moisture from you. But I just don't remember it's there--some shiny thing distracts me, or a complex but brilliant bluelight post with witty wordplay demands my attention.
You'll forget all your supplements eventually.