I did that several times, but only with a wetsuit. Which is not as bad....on the second dive, forgot to have buddy zip up the dry suit zipper.
Dumbest thing I ever did was also lucky. I was supposed to assist an OW class as part of my Divemaster certification. We arrived on the beach, the instructor looked at the waves and said "Sorry, this is not good. We have to reschedule the dives." Everyone went home... unaware that I brought all my gear except BC.
---------- Post added March 24th, 2014 at 03:52 PM ----------
Wasn't she supposed to turn on her own air?-Forgot to turn on the students air before she got into the water (How they hell did I forget to turn on the air!?)