The Mystery of the Douchebag....unsolved.

I went out drinking one night with the roommate and we observed one of our favorite bartenders kissing her boyfriend.  Our convo went as follows:
Big Greg "That dude is with her?". 
Little Greg   "I know right?  What a douchebag!".  
Big Greg (laughing) "What's a douchebag?" 
Little Greg   "That dude right there is!  Come on man!"
Big Greg (looking confused) "Well how is he a douchebag??"

Then it hit me.  I don't really have a working defintion of a douchebag.  I know some characteristics of one but couldn't explain it to my roomie.  It's a term a lot of us these days to kind of cover the jerk to a**hole behaviors we see on the daily.  And I realize I use it a lot.  Sometimes I even shorten it to doosh as in "what a doosh".  I mean what the hell is a douchebag?  Who is a douchebag?   I'll try to describe him but ultimately I'm open to suggestions or thoughts.   Hope I don't offend anyone and if so, I strongly suggest you fix it.  Here he goes. 

Is he the guy who wears extremely tight shirts to purposely show off the guns? .  Is he the guy who has the cheezy come on lines at bars  "Come here often?  I don't either because of my MMA fights".  Speaking of MMA, is he the guy who claims to be training for fights and his record is 0 wins, 0 losses?   Is he the guy who back door brags?  For those that don't know that one, it's when someone brags about themselves but sneaks it in the sentence. Ex:  "It's hard for me to watch football because their techniques are simplistic compared to when i played".  Is he also the guy who claims to have seen a movie but when asked his opinion on it suddenlly has loss of memory?  

The truth is I dont know!  I only know when I see the guy.  For the most part, they aren't terrible people.  They are probably insecure on some level and do or say things to compensate for that lack of security.   Someone may have called me a douchebag at some point in my life.  If so, I wish they would've told me.  So when you're out tonight, look for them.  If you feel compelled, talk to them. Coach them up.  They can't see themselves.  Only you and I can.  I'll do my part too.  Perhaps I'll start a Douchebags Anonymous group to be held at in a place with many, many mirrors.  Just hope it's not contagious.