Is changing who you are normal?

Well,when i was little up until i was 16 i was kind of a nerd.I use to have a high top fade and dress in preppy clothes,or clothes i don't wear now . I wear ed hardy,south,and wear stuff from pac sun.I always followed rules,and never wanted to get in trouble.I told my self i would never drink,smoke, or get tattoos,in which i do/have all the above.I have a buzzcut,and i'm lean but very built.I'm thinking about getting a gun to carry for protection.I'm a big flirt/player.And do what i want when i want to.Don't follow rules unless i want to.Etc why did i change so much?