My husband, who still has pcs, and when tired (which is almost all the time) can't remember things said to him 10 seconds before, will tell you he's doing good, and the concussion really doesn't bother him much. He also falls asleep within 1 minute of sitting down if you don't keep him busy with something to keep him awake, at any time of day, yet he'll tell you he doesn't have a problem with being sleepy. Somebody who's got such problems, is not necessarily going to be able to tell they've got problems.

Also, I'm remembering a college roommate who said, in the same breath, "Smoking pot doesn't really have a negative affect on me at all. OH, But then I lose things in the weirdest places...!!! Within a week, she went out the back sliding glass door to the shed at 11pm (why? I dunno, no lights out there, winter in Colorado, snow on the ground, temperature -22°F, yes 22 BELOW zero) and left the door wide open. All night. Forgot to shut it on a night when the temp was 22 degrees BELOW zero. But no, she suffered no brain effects from her minimal drug use.

Um....yah. Altered people are not the best judges of what is going on.