You can fail at things you love, you can fail at things you hate. One implication is: duh, do the things you love, because you could fail either way. You might as well fail at something you love.
That’s only one dimension to life though. Doing what you love—or think you love—certainly can be a bet to make you happier.
But it’s not always what’s constructive or effective. For starters, if you’re just getting started at something you love—say, you didn’t have a chance to gain a skill in your childhood, or during your teenage years—you’re probably not going to be very good at it. Are you willing to make a big bet that you’ll improve that much? Or can you keep the cash coming in while you practice?
Similarly, that thing you don’t love—and have developed a skill at—is there another way to make money from it, that doesn’t involve the way you’re currently doing it? Or can you position it to go in the direction of where you want, while making sure you take care of what you need?
Chasing what you want is one thing; making sure you have what you need is another. Don’t mix the two up. Make the trade between want and need carefully; when in doubt, make sure you have what you need before you try to take care of what you want.