It's simple, easy to satisfy and constantly tossing and turning, those two things are enough.
I thought carefully about why I became such a HAPPY ghost can probably be summarized as the following two points (seriously holding glasses).
The first point is easy to satisfy.
This is actually mentioned in many of the answers above, to a greater or lesser extent.
This point to me becomes: because easy to satisfy, so I always consider myself a very lucky person.
For example, I'm teaching in a small mountain village, and I haven't eaten meat in over a month, so I eat bean sprouts, cabbage, and potatoes every day.
One night when I was eating noodles I said, "When I eat noodles at home my mom will fry me a poached egg, if only I could be allowed to eat a poached egg here for once!" The next day, something suddenly came up at school, and the principal took a few of us teachers who had come to teach out to dinner, and the final entree turned out to be a bowl of noodles! Surprisingly on top! And poached eggs!
I was happy for days just because of this, thinking how I was so lucky so lucky~~so lucky~~there were many other things like this, so I always considered myself a very lucky person. Things that other people might take for granted, I take as a blessing, as a special favor from God.
The second point is the spirit of constant tossing and turning
Continuously tossing and turning, to find interesting things in ordinary life, to do interesting things.
Taking today's example, the place where we are teaching only has two days of vacation, and my home is too far away to go home. The same dormitory to teach are said to be meaningless, this side is not much fun, in the afternoon in the dormitory to sleep. I went to bed last night at ten o'clock, but I couldn't sleep, and then I thought, "We're the only ones in the school! There are only a few of us in the whole school, and no one is in charge of me, so I can do whatever I want! I'm not going to be able to do anything I want to do.