It's unpleasantly like being drunk.

So... if you're quite a "together" drunk then no problem.

I get quite annoyed at other people when I'm drunk and can't stop at three drinks (can stop at one or two though!) so one puff and nope, really didn't want it. A few hours later and I was thinking how stupid the midwives were. OK, they were being stupid but I shouldn't have been thinking about them!