When you’re doing something hard, focus on the fun part.
Many people make a subtle mistake, which is they emphasize how difficult it is to do something. They tell themselves writing is hard or running is hard or math is hard. And so on. The dominant thought in their mind is that this is hard to do.
And it is true these things (and many others in life) can be challenging.
Meanwhile, people who thrive in a given area are often emphasizing a completely different aspect of the experience. They are thinking about how it feels good to move their body rather than telling themselves exercise is hard. Or, perhaps, they aren’t really thinking much at all. They may slip into a trance during their run, a meditative rhythm.
But what they are almost certainly not doing is repeating a mental story about how hard it is to do the thing. Their dominant thought is about some element of the experience they enjoy. They are working hard, but with the fun part in mind.