What a load of poppycock.
The reality is that pursuing what you love is of marginal value at best, and is harmful at worst. Many people like myself find that going to work in something you love (video games) strips all the joy out of that thing and in fact removes something positive from your life. Usually doing "what you love" means going into a crowded field where lots of other people also want to work, which means you will have trouble getting a decent job and decent pay.
What actually matters to happiness in the workplace ?
1. Choose a job you can be very good at. There's just massive benefit to being one of the best in the world at something, or having a talent that's desirable or unusual. You don't want to be an easily replacable worker, because then you can be treated like this. This does not mean you have to be some superman, however. You could specialize in something that most other people don't want to do. Or you can get some licensing that makes you rare (like a crane operator or underwater welder).
2. Choose a job that doesn't tie you to a specific company or geographical location. Avoid jobs where there's basically just one employer in that field, or where all the companies are in the same city. Your power in controlling your life comes from the ability to move where you want to live, or change jobs if your employer treats you badly. You never know when something will go sour with a certain employer or you may have to or want to move for some reason.
3. Choose a job where the working conditions are pleasant. This means the physical environment of the office, the hours you have to keep, who your coworkers are. All of this is way more important than what you actually do for the work. A huge factor in this is the aforementioned freedom to choose from multiple employers - you don't want to be stuck having to accept the one job you can get, freedom to choose lets you pick an enjoyable place to be.
4. Choose a job with flexibility. This may vary for others, but for me the flexibility to work what hours I want, take vacation when I want, etc. is massive. Generally this means picking a job where you are judged by delivering some work product, not just putting in hours each day. Then you can choose your own path to make that work product. Obviously this could be software, but the same goes for custom bicycle frame builders, web site designers, etc. anyone who's running their own business or an independent contractor or just in a good employer situation where they give you product deadlines instead of work hours.
5. Choose a job with a pathway for advancement or a way to stand out.
6. etc... you get the idea
The important thing is freedom and power, not doing something you're passionate about. Passion is for love making and cattle. This is work.