Am I Normal or Not?

Ive been thinking about how my mind is always imaginating things. Ever since i was young I've always had a really creative and overactive imagination. Now I'm starting to wonder if its normal to always have a fantasy going on in your head while your living reality. I admit that whenever I feel that im sad, mad, or just over emotional or even bored I try to escape to my fantasy world that I constantly have, but I've seen that not alot of people think living in a fantasy in your head is normal most even think you'd be mental. Im 15 now and wondering if im showing signs of mental illness or just a normal over active imagination that i havent grown out of yet.