Getting back to playing poker after a long vacation

I just recently got back from a summer vacation and I didn't play any poker during that vacation at all. No online poker - No live poker.

So as I've slowly got back into my normal routine the last few days and got back to playing some poker, I found myself having to quit playing sooner than I did before. I would have thought after not playing for so long I should be able to just sit down and play for hours and hours and hours non stop, but my last few sessions I have had to cut short. I will start playing and after a couple hours I call it quits because I'm either not quite into it or just get impatient.

What's strange is there were times before where I have not played poker for weeks and each time I was able to come back and it was like I wasn't gone. I would play just as long as I did before I stayed away . This time, I'll sit down, play for 2-3 hours, and I had enough.

Do any of you go through periods when you just don't feel it when you're playing poker for whatever reasons?