Two factors affect your happiness. For most people, one of these is clearly dominant. For happy people, they are in balance.
The factor that decreases your happiness is all the things that don’t work. It is the bugs in your code, the meaningless bureaucracy you are subject to, and the constant deluge of bad news from our media. This information is constantly forced upon us from the outside.
The factor that can increase your happiness is all the things that do work. But the media rarely report good news, and your boss rarely comes by your desk to express his appreciation for all the systems that are working flawlessly. That means that you have to provide the good news yourself.
Make a habit of appreciating something every day. The code that runs just as it should, the train that was on time, the friend that called you. It is up to you to keep your life in balance.