What has changed?

So, I have been married now for 4 years and we have had a pretty easy marriage. My wife and I genuinely care about each other and I learn every so often that genuine become more genuine with time and experience. This is not the point though.

In these past 4 years my wife and I have been apart from each other very few evenings. Sometimes we have a late night were I am working while she is sleeping or even where I have played or worked through the night and she has sent me to bed when she woke up. Those I am not counting, I mean nights where we are separated by more than walls and door but by miles, city limits, and/or state borders. I am a student and so such is not required of me in a profession (currently, who knows about the future).

Last time that I remember is when my wife went to Disneyland with her sisters some time ago (this is my ambiguity that means I am terrible with dates and time keeping on things like this). On that occasion she was gone for 5 days (I think) and in truth I missed the company of my family but probably enjoyed the peace of being alone more than I missed everything else. They were all back (meaning her and the kids) before not having them wore on me too much.

This time around, my wife with the kids are gone for a week visiting her mother. I have not been able to enjoy the peace and quiet because I have missed everyone so much. I wish to hold her and have her here with me. I want the joy in my childrens' faces as I chase them through the house on my hands and knees. I miss it all. The craving is very poignant and has hit me hard, so what has changed in the year-ish gap since the last time?

I don't know. But I think that I'm going through withdraws. Maybe that one friend was right when she told us in high school that we were addicted to each other. Time makes quitting harder from what I'm told.