This is all in jest (and I've obviously got too much time on my hands) but being around serious pool addicts for so much of my life, I've realized that most guys will fall into one of these 9 categories:
1. Know-It-All Railbird: Constantly critiquing everyone’s game and practice sessions. Spends most of his day sitting amongst anyone who can stand his mouth. Drinks too much coffee and/or smokes too many cigarettes. This person likes to side bet $5-20 on a $3,000 match, thinks he’s “part of the action” and gets more upset if he loses than the loser himself.
2. Nice Guy Railbird: Is at the pool room every time you go and mostly keeps to him except for the friendly stares and “hellos”. You will see him practicing occasionally but only on his favorite table. Good tipper to the wait staff and well dressed. Some wonder if he is a cop looking to bust someone gambling.
3. “Action Man”: A self given name to a guy who chirps about high stakes action all day long but very rarely gets it going. Flashes money or talks about how much money he has, makes or gambles with. He’s crude, swears a lot and has no concept of speaking quietly. Completely self absorbed, enjoys the spotlight and believes that everyone thinks he’s God’s gift to action when in truth, we all wish he’d just stay home.
4. Sidekick Groupie: A solid “B” player. Always around and worships his A/A+ player best friend. Whenever there is talk about pool, he will find a way to get his friend’s name in the conversation. Follows his friend to tournaments and will sometimes stake him.
5. The Student: Can be well mannered to a total jerk but this person is on the brink of dropping out of either high school or college because he is spending increasingly too much time at the pool room. His dream is to be the “best pool player in the world”. Players don’t take him too seriously and try to get into his pocket since they assume he’s got money and wet behind the ears.
6. The Wacked Out Player: A “has been” or a “never will be” since he is always high on something and rarely sober. Always broke, has terrible hygiene, a big whiner, and can be seen wearing only 3 outfits interchangeably throughout his entire life.
7. Hermit Short Stop: Quiet, good dresser, well mannered but very reserved, this person has the ability to beat anybody but not very consistent. Skill can go from shooting lights out to dogging easy outs but a “nice guy”.
8. Metrosexual Pool God: An A+ / Professional player, gets along with virtually everyone, has good hygiene, well mannered, good build, only gets out of hand with too many drinks but even then is OK and has actually shopped at Nordstrom for himself.
9. The “I Am God” Professional: Is a strong player but feels the world owes him something. Is condescending to anyone who does not play at his level and is an ass to those who are. Always fidgets with his cue, asks too many questions at the Player’s Meeting, annoyingly watches too closely as you rack the balls before he breaks, mutters loudly when you get a good “roll” and probably kicks small animals outside the pool room.
For those of you who laughed, that's cool.
For those of you who got offended ... well, read your description again and learn a little something about yourself. Enough said. 
1. Know-It-All Railbird: Constantly critiquing everyone’s game and practice sessions. Spends most of his day sitting amongst anyone who can stand his mouth. Drinks too much coffee and/or smokes too many cigarettes. This person likes to side bet $5-20 on a $3,000 match, thinks he’s “part of the action” and gets more upset if he loses than the loser himself.
2. Nice Guy Railbird: Is at the pool room every time you go and mostly keeps to him except for the friendly stares and “hellos”. You will see him practicing occasionally but only on his favorite table. Good tipper to the wait staff and well dressed. Some wonder if he is a cop looking to bust someone gambling.
3. “Action Man”: A self given name to a guy who chirps about high stakes action all day long but very rarely gets it going. Flashes money or talks about how much money he has, makes or gambles with. He’s crude, swears a lot and has no concept of speaking quietly. Completely self absorbed, enjoys the spotlight and believes that everyone thinks he’s God’s gift to action when in truth, we all wish he’d just stay home.
4. Sidekick Groupie: A solid “B” player. Always around and worships his A/A+ player best friend. Whenever there is talk about pool, he will find a way to get his friend’s name in the conversation. Follows his friend to tournaments and will sometimes stake him.
5. The Student: Can be well mannered to a total jerk but this person is on the brink of dropping out of either high school or college because he is spending increasingly too much time at the pool room. His dream is to be the “best pool player in the world”. Players don’t take him too seriously and try to get into his pocket since they assume he’s got money and wet behind the ears.
6. The Wacked Out Player: A “has been” or a “never will be” since he is always high on something and rarely sober. Always broke, has terrible hygiene, a big whiner, and can be seen wearing only 3 outfits interchangeably throughout his entire life.
7. Hermit Short Stop: Quiet, good dresser, well mannered but very reserved, this person has the ability to beat anybody but not very consistent. Skill can go from shooting lights out to dogging easy outs but a “nice guy”.
8. Metrosexual Pool God: An A+ / Professional player, gets along with virtually everyone, has good hygiene, well mannered, good build, only gets out of hand with too many drinks but even then is OK and has actually shopped at Nordstrom for himself.
9. The “I Am God” Professional: Is a strong player but feels the world owes him something. Is condescending to anyone who does not play at his level and is an ass to those who are. Always fidgets with his cue, asks too many questions at the Player’s Meeting, annoyingly watches too closely as you rack the balls before he breaks, mutters loudly when you get a good “roll” and probably kicks small animals outside the pool room.
For those of you who laughed, that's cool.

