When my friend randomly suggested that we try a very ambitious hiking route, I knew it would absolutely suck if I didn't train for it. I got a gym membership and told myself I'd at the very least set foot in the gym 7 days a week for the first few weeks, just to build the habit of going. I was motivated to make sure I didn't slack off and ruin the hike for the group by being undertrained. A few months of that and the hike went great.
When we got back, though, I found it felt weird to not go to the gym in the mornings before work (as a decidedly NON-morning person my friends and family looked at me like I'd grown a second head when they heard me say I was working out before work). I started running outside on days the gym was crowded, and it felt good! In the nearly eight years since then, there have been only a handful of weeks where I didn't go for a run—I genuinely really enjoy it, no motivational tricks required.
Another thing is that we must distinguish between listening to music and eating a donut as reward. One helps people foucus while the other makes you gain weight..
As a more concrete example, as soon as you learn to enjoy learning as an activity, it becomes fun, whatever you are studying. So you only need to learn to have fun while learning. Start with simple things, make it a game, find beauty in what you are learning.
But sometimes the problem isn't motivation. Sometimes it's energy. Sometimes you really do want to do it, to the core of your being, but you're just too fucking tired. That's a very different problem.
So, just start liking the things you don't like? Sure, ideally that's the solution you want, but it's not exactly actionable advice.