Things change over time?

I'm sorry that I've broke my "one journal per day" promise as I have learned a few lessons on friendships issue. I wonder if really things change over time? In the first place, I thought that only electronic gadgets will change over time but I never knew that friendship can really change within months. A close friend of mine - Mr.E, whom I regard as one of my best friends since high schooldays.

E was working in overseas and during those "lepak" days of mine, we used to hang out always whenever he's in town. When I was out of town, he used to send regards to me and asking me when I'll be back to our hometown so that we can hang out again like the good old days. Things change over time, I'm quite fed up about his attitude when I'm back in town as he changed into another person and he didn't even give a damn about me. I was thinking that when I'm out of town, E'll keep asking to come back to meet him this and that instead he didn't kept his promise when I'm back in town. I can't deny I'm petty and disappointed about him but I really can't buy his excuses that he gave me when we couldn't get to meet up. I was thinking, we used to be good buddies but now you are able to give up everything just to please your girlfriend. WTF?!