I've written about how you might want to experiment in order to find something better. When it comes to your career, for instance, you might want to try different projects and companies in order to find something even better, even if what you've got now is the best you've ever had. Especially if you haven't experienced that many projects yet. That is, changing things around could help you find something better.
Of course, it's a bit more complicated than that.
Some valuable things aren't so easy to change around. Relationships are an example of that. In order to achieve an enjoyable, long-lasting relationship, either professional or personal, you're often better off investing time and energy into it. That may not be enough, since the other party must do the same. Even then, you should evaluate whether the relationship is beneficial as a whole - it's quite possible you'll find a more fulfilling project elsewhere.
If you're more risk averse, you can try to grow the relationship, find a better version of the it. Perhaps you can change something within the relationship, create an experiment of sorts. What happens if you try to vary your communication style, workflow, switch to other tasks, or suggest some other new ideas?
There are lots of ways of investing in a relationship, other than spending more time doing the other party's bidding. Try them out, and don't be afraid of letting an experiment fail. Just try something different!