I Miss Tokyo.

Come back to London. I was missing London during the first few days of my stay in Tokyo, but now I am missing Tokyo. I really enjoyed the party last Friday, but I can't throw a party in the same way in London. This fact made me even feel I didn't want to go back to London... I usually don't feel this kind of backward emotions (Is "backward" the right word for this? I don't know how to put this in English). I always look forward, though I sometimes stop moving forward. But never going backwards. So this upset me. Why do I feel like this?