To be honest, before I ever started training I NEVER thought I could fight. Now, I've been training in mma for the past six years. Brazilian Jiu Jitsu on and off for the past 6 years, and then some basic kickboxing the past 4 years, and the past two years I've been working on my boxing and wrestling (and of course still trying to keep up with my jiu jitsu and kick boxing) . I also do have an amateur Pankration fight under my belt.
However, even now despite all the above I still don't really think I can fight or choose not too. Why...well for pro fights...I'm just not good enough and/or have the dedication or desire to make it, the ends doesn't justify the means for me. For street fights, choosing to get in one is just plain stupid despite whatever the reason. There are just too many factors that come into play that despite how much training you may have can seriously alter the outcome...i.e. If I were to fight a guy who was Bob Sapp's size and had no training whatsoever, that guy would still demolish my tiny 5'9 200 lb ass. Jiu Jitsu doesn't teach you how to finish a triangle when you're on concrete getting kicked in the face by the dude's three buddies. Muay Thai doesn't teach you how to defend a knife attack or a gun shot. And even if you manage to come out on top, I don't need to go to jail and have a black mark on my resume for some stupid reason like a bar fight.
Hell even most Krav Maga instructors (which is the ultimate self defense) will tell you...if you're getting mugged...just give your wallet and walk away...as you should never risk your life and the stuff they teach is only for life-death situations.
~G
p.s. I admit people who walk around like their tough shit in bars/clubs because they train once a month and wear affliction and tap out shirts do annoy me, but I leave it at that...they still put money in the sport (which is still growing like ihav.net). However, the people who embarrass me, their gym, and the sport...are the people from who do train regularly and feel the need to "educate" these people acting bad by trying to start fights with them at the club/bar because that person is wearing a tapout/warrior wear/affliction shirt.