I had this feeling after I met Bono twice in one day. It was probably one of the best days of my life, not just b/c I got to shake Bono's hand, but I made some great new friends and the whole experience was a blast and exceeded all expectations. You'd think I woulda been one happy cookie, but the next day was honestly the most depressing day of my life. I'm ashamed to admit it, but physically I felt worse on that day than the day my good friend died of cancer. I don't know exactly why - maybe b/c I had gotten sick from our 24 hour wait in sub-freezing temps and all the emotional highs. It was like I wanted to crawl into a hole and die. I think it's a legitimate feeling when you really are truly that emotionally invested in something. I don't really know how to help you. When it happened to me, I got over it after a day or so. I got my pics developed and shared the experience w/ friends and in doing so it became more "real" and I felt better.