Why is he acting this way??

we broke up a little over a month ago. he broke up with me and I was trying to play it cool, but I was very hurt. we were in a long distance relationship and after i flew home I get emails from him wanting to know how i was settling in, etc. my response was to be so over the top happy as i did not want him to know how hurt i was. we've since stopped communication, but the last time he emailed me he was acting and sort of like i had been, like life was great and said he had been "super busy", not his language style at all. anyway, i know we've broken up, but i'm just curious as to why maybe he started acting this way.