This is a hard question, and most people rarely think about it normally. ( I guess. XD )
I don't have one absolute identity right now, since I have two (3) distinct "modes".
1) My 'normal' self. Only 'normal' in that way, that this is the more accepted behaviour from me in my current environment. The one who does the right thing, acts reliable, colder, etc... The one which I dislike, but I know that I need it to survive. >.<
2) 'Pup mode': My more child-like side. I like it more, I don't have to care about the stupid expectations, I just walk around the city, explore unknown paths in the woods, play with May bugs, take a nap in the middle of a field, stare at the sky, pick up the garbage other threw away (<- While doing this I think about that, how annoying humans can be...) and have fun. Although my collar (I got a new one not long ago, and I'm lovin it. :3 It is a really cute one. ), and the fact that I'm smiling (!) creeps some people out. XD But that doesn't matters since I don't really want to talk to them while I'm this way.
[3) The 'Leave me alone!!' mode: Not really distinct mode, but part of the 1st one, and worth mentioning. When I have a bad mood, and I don't want to trouble myself with humans...]
I hope this is a satisfactory answer.
TomarctusHU