Is it normal to feel multi-personalities?

Its annoying when you know who you are but when it comes to being with someone else whether you just met them or youre friends, you don't feel like who you really are comes out; its almost like an intimidation factor but not really. For instance, I like hip hop music and i really appreciate it, im into it, but when it comes to talking to others who are all open about it and start rapping to the radio while Im just there rapping in my head, I feel like great they will never guess Im a hip hop fanatic and if they ever do theyll think I just started to or im a poser but really Ive loved it the whole time. I love to party and drink but when im with these like psycho pple I get reserved and they probably think Im a party pooper or something when I just love to go out. That sounds like intimidation right there but sometimes I dont get intimidated yet my personality doesnt come out and thats where I feel these multi-personalities come out. Because of all these different types of people overshadowing me, I feel like a different person like i.e, hmm maybe I dont like hip hop or partying isnt for me when i love both but others seem to make it go away.