Is it normal that i am both sad and happy?

As of right now I am both sad and happy and still trying to figure out how that could be. Somedays I'm super happy and just love life and want everything to do with people, and other days I'm just kind of weird and depressed and want nothing to do with people. It's quite weird and I feel like I have differing personalities with these two different moods, but then again doesn't everyone.