Can someone shed some light on what Cat 1-5 means?

Cat 5: I have no idea what I'm doing but think bike racing might be fun. I ran/swam/rowed in college, so this can't be that different, right?

Cat 4: I have no idea what I'm doing, but my carbon wheels help me crash at higher speeds. During races, I find it helps to verbalize my every action. Safety of the pack (though I'd call it a peleton) is ensured by yelling "Hold your line!" in every corner. I have seen Breaking Away.

Cat 3: I won a few races as a 4, so I guess you could say things are getting pretty serious. I cracked my carbon wheels as a 4, so I'm back on aluminum hoops. I can beat up most of the guys on the group ride, unless I annoy one of the 1/2s and they make me beg for mommy. I have seen American Flyers.

Cat 2: I'm a legit road racer now. My first P/1/2 race nearly broke my will to live, but since quitting my full time job and moving in with my girlfriend, I'm getting faster. Every upgrade point is celebrated like a birth in the family. I rub elbows with the pros in certain races, and while I try not to show them I'm impressed, I tell all my friends about it after the fact. The weekly local training race is now used as a recovery day. I have seen Deux Secondes

Cat I: After breaking up with my girlfriend, getting kicked out of my parents basement, and sleeping in my car for the last 6 months, I finally got my 1 upgrade. I'm a demi-god who can take all the shit the pros can throw at me, though I'm acutely aware of how little I can throw back. I can't imagine getting much faster than this, but I really don't have much else to be doing with my life so I continue to train. I have been in the background of a photo on Cyclingnews

Domestic Pro: I can finally afford indoor plumbing again. Most of us understand this is as good as it's going to get, so we spend most of our time partying, but only after the training is done. I have raced with someone who has doped. I show up to the occasional local crit and spend 90 minutes mother ducking the entire field around. Then I win the field sprint and head out to finish my century for the day.

from reddit.