Ask any fit or sporty individual you know. They don't do it because they have to. They do it because they want to.
The boredom you mentioned is natural. Everybody gets it at the exact same strength and at the exact same moments. The difference is that some people are disciplined enough to continue and burn through it. And only then you get to see the fun and enjoyment part.
Discipline is king. With anything else you're just lying to yourself. Nobody will create the perfect environment for you to be comfortable with physical effort. You're the one that has to do it.