Why is the man not really surprised that his parents are moving?

M:  I just found out that my parents are moving.
W: Mmmm. Are you surprised?
M. Well, not really. They’ve been trying to sell their house for six months to a year now.
W: Oh, well, I thought they liked it where they were.
M: They do. They love it. But they’re getting older. Dad wants to live in a smaller town. And Mom Says she’s sick and tired of the fast pace and taking care of the house, you know.
W: Hmmm. So where are they going to move?
M: You’re not going to believe this!
W:  What?                                                                                    ,~
M: They’re going to Mexico. Can you believe it?
W: Oh, my gosh. You’re kidding.
M: Nope. They’re going to San Miguel de Allende. It’s this gorgeous little in the mountains.
W: Wow! I’ve never heard of it.
M: Ah.... it’s about 150 miles northwest of Mexico City.
W: Wow! Do your parents speak Spanish?
M: No, but they’re going to learn.
W: Wow. That’s a big change. Why don’t they stay in the U.S.
M: Well, they have always wanted to live abroad. Now that they’re retired, they finally get to do it. And my dad, he adores Mexico. He’s been there six or seven times at least. W: Wow. Sounds like this is going to be quite an adventure.
M:  It should be. And San Miguel -- it is stunning. The government has made sure that there is no new buildings ever built there, so the traditional feeling of the town ... well, it’s been preserved. Oh, and they make pottery there, which is perfect for my mother because she collects the stuff.
W: Oh, that’s great for her. So, I guess now you’re going to have a place to stay in Mexico. M:  Yeah....
W: And a place for your friends to come and visit in Mexico. So, when exactly are they moving?
M:  In a couple of months. They have to pack up and take care of all the business here. I’m going to help them with the move. I may even try o stay a couple of months if I can swing the time.