My AOW deep dive was valuable in some regards, but perhaps not as intended. I took AOW right after OW, where I had done the checkout dives in warm water. The AOW deep dive was my second dive in a dry suit in cold water (37F at depth), in poor visibility. I was also not feeling well that day and was squeezing my butt cheeks together during the entire dive to prevent an accident from happening. The skill was a simple counting and signaling exercise; I did a little better at depth (70'ish), because obviously I had done it before at the surface. But I also learned about myself that the combination of poor conditions, unfamiliar equipment and dive site, me not feeling well, and a small problem that I didn't fully understand while down there (the DM had a problem with a leak from a pony, and the instructor was working on it while we were kneeling at the bottom, waiting do do our skill), all added up to making me a bit anxious. Nowhere near panic, but I was surely watching my pressure gauge ticking down while we were sitting down there and thinking about what I would do if I somehow had to abort the dive on my own and at what pressure I would be forced to do so. Maybe a bit of dark narc at work here? And I was really glad once we were done with the timing exercise and swam back to surface. I have been considerably deeper in cold water since, but never had that feeling again.