This is the drinker who acts as though college was 20 years ago, not 3. Apparently ashamed of his past, he vocalizes his newfound distaste for house parties and keg beer. Though you could all present photo evidence of him being formerly the most "college" of all, he can shower you with all the wine knowledge he needs to convince you that that was a long time ago. He brought his own craft beer to the party, and no, you can't have one because it's one of those four-bottle packs. Also, don't ask him to be your partner in beer pong - "he doesn't even remember the rules."
Young adults have an existential crisis every hour or so and sometimes they'll need to talk it out with you. Most of us only seek this amateur psychology in times of sobriety, but this guy seems to seek counseling the second the drinks are poured. While you're trying to unwind after a long week of your own introspection, he is dumping "What if I never find anyone?", "Should I just move back home?", and "Honestly, am I a good person?" all over your good time. Be a good friend and muscle through this buzzed up therapy session. There may soon come a day when you too need a little intoxicated life coaching.
This is the guy who seriously misses being able to walk, bike, or drive a stolen golf cart to whatever party the group wanted to go to. He is the designated driver tonight and has been ready to go home since the moment he got there. What The Furious DD needs to realize is that this title has its benefits. Women will immediately know you're responsible and while amidst a sea of drunken fools, your mere ability to form sentences will make you look like James Joyce. So enjoy that water on the rocks, and if you don't pull any numbers tonight, you have nobody to blame but yourself.
This is the opposite of The Patient. Instead of being tormented by his own consciousness, he is perpetually inspired by it. Assuming this sports bar is a Greek symposium, he'll lock you into debates over the meaning of life, the difference between the brain and the mind, and the bright distant future where people like him have inevitably risen to power. Since he can't get paid for his B.A. in Philosophy, he's making damn sure he gets attention for it. Funniest part about this guy is that by the end of the conversation he will be fully convinced that you made some pretty astounding breakthroughs together. He's probably giving you too much credit in this accomplishment, since you barely got a word in.
He's convinced that the stresses of his office are interesting. The Decompressor was the kid in college who spent most of his inebriated hours talking about "this God damned paper" or "my terrible thesis". He's only gotten worse in his young adulthood. Instead of whining about topics you actually have experience with, you're hearing about "fucking Beth in accounting" or "Gary, the fat I.T. guy." Listen closely and you may find that he's also making sure you know how much responsibility he has at work. Watch out for negative comments about the people who work immediately under him - the intended take-away being, "I have people who work under me."