Is it normal to kind of enjoy fighting?

I had a fight on the last day of the school year (About 2 weeks ago), I've had a few fights before this but this fight was probably the longest and most "brutal" so to speak, I got a black eye and he got a busted nose, I'm 14 and he's 17, but for some reason when I was fighting I felt an adrenaline rush, like I was enjoying it, which I never used to feel. I started boxing a couple of weeks before, and I was decent at it, but after the fight I've really improved, and at sparring I'm alot better, infact I now spar with grown men in their 20's, and I feel an adrenaline rush then too, especially when I'm landing hits. In my other fights I never felt like this, so I'd just like to know if this is normal. Thanks in advance.