One type is people who weren't satisfied with their careers from the beginning of it. I mean they wanted a higher class job but becase of some problems, they couldn't get it. So they had no choice but to get those unsatisfying job. In this case, people have enough possibility to be unhappy with their careers later, too. So in this case, because of their mind that they had already they become unhappy.
The other type is that people who become sick and tired of there career as time goes by. There is no problem at first but while they work, they are getting know that there are some sort of problems. The problems can be a promotion, salary, or relationships between coworkers etc. However if those are not the reasons, people can be are just fed up with their same everyday. Because familiar things sometimes make people boring or tiring.
There are a lot of reasons people become unhappy with their jobs. And the reasons are divided into two.
First, people who weren't satisfied with their careers from the beginning of it. I mean they wanted a higher class job but because of some problems, they couldn't get it. So they had no choice but to get those unsatisfying job. In this case, people have enough possibility to be unhappy with their careers later, too. So because of that mindset, they are already become unhappy.
The other type reason is that, people who become sick and tired of there their careers as time goes by. There is no problem at first but while they work, they are getting to know that there are some sorts of problems. Problems can be a promotion, salary, or relationships between coworkers etc. However if those are not the reasons, maybe people can be are just fed up with their same work every day. Familiar things sometimes make people bored or tired. (Bored and tired are feelings. Boring and tiring describes someone or something that makes you bored.)