In my 20s - and was going out to dinner to celebrate a friend's birthday. Her (older - in 30s) cousin, really wanted me to get drunk cos I'd visited their (cousin & wife) place quite a bit, but had always been very careful - brought up to believe in moderation in drink (but not guilt repression etc). I mixed drinking with smoking (which I rarely did) and got drunk and had to leave the table to get sick in the loo, and later went home and was sick again; have never felt so awful in my life. And I didn't want to face or tell my other flatmates, or family.