Programming ruining my memory?

Over the past few months I've been successively spending more and more time working on developing a computer game. Now, it was hardly noticeable at the beginning, but as time has gone on, I've been having more and more trouble remembering things. Sometimes it's in my every day life, like, I forget where I'm going, but more often than not, I'll be working, and I'll switch between two files, and then completely forget why I did or what I'm doing in the new file.

Has anyone had this problem? Or do I just have a case of programmer's-island-fever?