I still THINK about him after a couple of years?

i grew up with him and we became really good friends..from what i can remember im pretty sure he like me back then too...i went to middle school with him and then i moved like 20 minutes away to a high school the summer before my freshman year..I've been having a couple dreams about him...even on vacation [just got back] i saw his name printed on the sidewalk.....my friend still goes to the high school i would of gone too and i saw the yearbook...dam he looked so grown up since 4 years, i almost started to get teary eyed, i heard he has a gf now with some girl we went to middle school with, im kinda jelous but whatever...why do i still lust for him? is he just someone i will always have in my heart? im planning to go visit my friend's school once the summer is over