He still does it occasionally, and has a couple 2-3 night school meetings he has to attend every year and now I actually look forward to those times, just to have complete alone time. I buy snacks that I love, and watch scary movies (he doesn't enjoy them) on Netflix. I don't cook, at all, when he's gone either. 
I love quiet too. A lot of times if DH is gone I don't even have the TV or music on. Just. Quiet.
Reminds me of the first time DH had an overnight trip for work, it was after our kids were grown and gone and I had never, ever, spent a night totally alone. Ever.
I was nervous and remember even crying as I watched his vehicle leave the driveway.
But! I quickly got over it, and after that first time and me realizing I would be totally fine being alone I loved when he had to go away for work.
DH used to be gone 2-3 weeks a months. The kids were gone on their own. I loved it. Quiet. We lived in a rural area.
Then we moved and he still traveled some. But telecommuted, so home more and made a lot of messes!
Then he retired and now he is here 24/7, I so enjoy when he has a meeting somewhere.
The kids and grandkids live close by and come over at least 2 times a week. I love having them close, but it is nice to have quiet when they go home
It has been a real adjustment for me. I go upstairs into my room (computer/ scrap book room) to be alone.
I feel the same way. 
I love quiet too. A lot of times if DH is gone I don't even have the TV or music on. Just. Quiet.
Reminds me of the first time DH had an overnight trip for work, it was after our kids were grown and gone and I had never, ever, spent a night totally alone. Ever.
I was nervous and remember even crying as I watched his vehicle leave the driveway.
But! I quickly got over it, and after that first time and me realizing I would be totally fine being alone I loved when he had to go away for work.
I am very extroverted and since it is just he and I in the household, I have had to learn how to back off and give him his space when I see the signs that he is needing it. He is such a sweet kid he would never deliberately tell me to go away because he wouldn't want to hurt my feelings, but I can generally start to see the tension in his shoulders and face when I have not given him enough time to be by himself (even if that just means being in the same room together but letting him listen to his headphones without trying to talk to him, etc.). We've gotten it down to a pretty good rhythm now - he knows if he hangs out with me he can relax and have a good time because he will have "his" time later. We call him an extroverted introvert, LOL, because he is social, just with a small amount of friends and he is totally ok on his own. I'm actually very proud of his independence, and I think it will serve him well going into his high school years, as he is really not swayed (much) by peer pressure.
Just about the time you finally get used to it, they'll leave for college. And then you'll have too much alone time.
My son is an only and is almost 13, and if he doesn't get a certain amount of alone time, he gets very cranky!
