Two types of people

There seem two be two types of people in the world. Or, perhaps more precisely, two attitudes among people:

• There are people  who are happy with what they have. Yes, they want more, and some of them work hard to achieve more, but if they do not achieve it, they do get dispirited, because they are quite satisfied with what they have. They also seem understand that in order to get something else, they might need to sacrifice something they already have, and they may not be willing to.
• And there are people who are very rarely happy with what they have. They always think that things could be made better. They try to improve everything, and achieve more, even at the risk of losing what they already have. Once they get there, they miss what they have lost. And they continue looking for the next improvement.

The first group of people are the backbone of the human systems - the family, the society, the workplace. They are happy, they maintain positive atmosphere, and they remove the threat of the unforeseen change. They are friendly, they care, and they are very much liked by the others.

The second group are the ones that move and change things. They may be grumpy, sometimes aggressive, never visible satisfied (except for the moment when they have achieved their goal - but this satisfaction does not last long). They seem to be focused on their own target more than the other people. They can be perceived as threatening.

Everything is good in moderation. The first attitude, applied in excess, may turn into stagnation, opposition to any progress and innovation, reluctance to identify and apply the "new ways" (if all people were happy with hand washing, no one would have invented the washing machine). The second, in its extreme, can threat with violent revolt and the destruction of the well established,  working, and generally accepted order (most revolutionary political changes in Europe were extremely violent, and the cost to the societies was enormous - look at the October Revolution, or French Revolution, one may argue whether the huge human sacrifice was ever necessary).

Anything in between is just fine. Of course there are multiple dimensions of human personalities, and here I am talking only about one of them.