It's been said that every 33' is equivalent to downing a shot of hard liquor. Are you just really used to downing hard liquor? Kidding! :) Everybody's reaction to narcosis is different, but it does happen to everyone. You are smart to only go to those depths when you have a good reason, instead of just so you can say you did it.
Training could be a valid reason. Which agency were you taking your Advanced cert with?