How long will it take for me to get over this lost friendship?

I am a 37-year-old female. He is a 46-year-old male and ex-coworker from 1998. We were friends then, then he had to work elsewhere, and we didn't get back in touch until 2007 at which time we became very close friends (platonic). For reasons only known to both of us (too personal to go into, and - no - it doesn't involve sleeping around and no talk was involved), our friendship gradually just died starting November of 2008. This was initiated by him as he became gradually became very closed-off to the point to being a jerk (I asked him about that eventually and he claimed everything was OK). We both ultimately chose to go our own ways without animosity involved. I really do miss him, but at the same time I'm "finding myself" more since not communicating with him, i.e., getting into my piano more, working out again, etc. (We used to talk for several hours a day). There are still times I will think about him without warning ... Will this ever p?