Is it ok to smoke marijuana 2weeks after a concussion?

No: I rarely ever endorse marijuana use. There are a few medicinal uses including for chronic pain, but this is prescribed only in very special and highly controlled circumstances. Marijuana use during concussion recovery is an especially poor idea.

Not the best: Thing for a brain that is trying to heal from an injury. Marijuana in younger people (and 23 is younger), especially if heavy and regular use, can impair intellect, reduce ability to learn and remember things, and wouldn't be what i would recommend after a head injury.