The feeling

Have you ever felt like your heart is beating fast when you see someone and you thought it was a heart attack about to happen and it turn out it was not a heart attack or when you feel like you are ten feet of the ground but you are only stuck to the ground by the gravitational pull haha i wonder what is that feeling call its hard to imagine but that had happen to me a lot of time but i dont know how to explain it because i am new to it. Well i hope it would not go away because i really like the feeling even if it was just a moment and it will only happen if i see a certain some one but i will treasure the feeling forever and never give it up no matter what happens. I hope the feeling wont disappear but what if it did what shall i ever do!!!!!