Curren$y -- I Missed Wiz Khalifa's Wedding ... 'Cause I Was Too High

They say weed can make you forget things ... like when your REALLY good friend is getting married -- just ask rapper Curren$y who blew off Wiz Khalifa's nuptials because he was too baked.

Curren$y -- a huuuge rapper who's worked with everyone from Snoop to Lil Wayne, Master P and, most famously, his close friend Wiz Khalifa -- was in NY for a hip hop awards show when he dropped a truth bomb about why he wasn't around when Wiz tied the knot with Amber Rose.

"We were totally like baked and I totally just smoked off my appearance," Curren$y said ... adding, "But he knows it's love and we definitely spoke and it's all good."

If anyone would understand, it's Wiz ... who's equally passionate about the green stuff. Just ask that one guy at the airport ...