I drifted off for a while too (hey, that should be our new refrain
).
In my case, it was due to the forum switching to V-Bulletin. I lost my password and couldn't get it back and just got confused and left. Then, several months later, I tried again and miraculously my correct password managed to get to me without any major hindrances on the way. So I came back.
After returning, I mostly lurked in the Shadows, reading a lot but not posting much. I guess I've been posting a lot more frequently of late, and have had fun acquainting myself with the newer (joined after 2005) members, especially in ME Mirth.