I think the longest I went without brewing was nearly 6 months and it drove me batty.
It was while I writing my book at the same time my partner and I moved into together for the first time. She wanted my help doing all the decorating, moving, unpacking,etc that one is wont to do when one moves.
My days during that period were - up at 8:30, go to work at 9:30, work until 6:30, come home, cook dinner, hang out until she went to bed at 9:30-10pm, fiddle for about an hour and then write until 4:30 in the morning.
That went on for 3 months and then afterwards I just couldn't get my butt in gear for the next few months.
Of course, the first time I brewed, it felt like a rusty set of skills, but I got the hang of it and Amy even commented after I was done: "wow, you seem much more relaxed now."
But yeah, every time I move.. yeesh.