Ahaha, that alcohol thing is good. I tend to try not to overdo it with alcohol, but once I was totally drunk. I could not remember everything of what I did that night at first, but slowly got most of my remembrance back (mostly with some of my mates help). All agreed that I was ridiculous funny and silly, they had lots of fun with me. Someone said she has never seen me like that. I am kind of emberassed to write it even here what I did, so I will leave it for me :P
But I will give a try to bring this discussion on a more serious level. Well, it is not that I never show any emotions and feelings. Mostly I will show when I am funny and I am with comfortable people, but I still don't express them fully. Mostly smiling instead of laughing and if laughing, I will try to not laugh too loud. Showing that I am sad is very hard for me, you will see me very very calm then and nearly not talking at all. So I do express my feelings, but in a very weakened form. Only when I feel really comfortable I will show them a bit more freely. But alcohol amplifies my emotional expression (but it must be with people I like), though I will still then not totally forget myself.
Expressing feelings in written form is a relative good way for me to express my feelings.
edit: Sarcasm I am good with. Showing angryness happens to me when I am REALLY angry, so not too often - in a weaker form to strangers, but with my parents it can get cruel.