You can convert speed times to MPH in your head, but you can't remember your own cell phone #.
Your ear is as accurate as any tachometer.
Your right bicep is noticeably bigger than your left.
You tend to walk in a wide left hand circle.
You have a large collection of left hand gloves, left over from all the pitting gloves you've gone through.
You have a safety thong tan line.
Your conversations include dope, pipes, needles, and syringes, and no one bats an eye.