Why does kissing feel so weird?

I've been snogged many times in my life, I'm a mature woman in her forties, but I was snogged last weekend on the dance floor by a guy I was dancing with, I felt swept off my feet as my heart lurched, I was so shocked by my reaction I still haven't got over it, why at my age can someone shock me like that? I don't like feeling out of control of my emotions, it scares me that he made me feel like that