Well-meaning people will tell you that the best way to achieve something is to move out of your comfort zone. But, the best way to make great progress isn't to push yourself as much as possible. Instead, a heap of studies show that whatever area of life you're looking to improve in, your best bet is to aim for something known as "the zone of proximal development."
This "zone" is just outside of your comfort zone. Instead of making you uncomfortable, you're able to stretch while not being too far afield from what you know. It allows for healthy and gradual growth.
Another similar concept is author James Clear's "Goldilocks Rule" concept, which finds that one of the best ways to stay motivated is to work on tasks of "just manageable difficulty." According to the Goldilocks Rule, humans experience peak motivation when working on tasks that are right on the edge of their current abilities.