Yes, sometimes it is much more easier to play happy especially for being in public or with a big group of people. Sometimes you also don't want to go over and over and over about the topic you are sad about maybe, just to be able to heal your wounds until the point is reached that you can open up to others, at least that is how it goes on for me sometimes.

I live in Tsukuba, around 50 minutes from Tokyo, and you?