A useful challenge leaves you curious enough to return after the first attempt.

The right level of difficulty is not the one that proves something. A challenge that crushes you produces avoidance, and one that you clear immediately produces nothing at all; the useful kind ends with you still thinking about it on the walk home. Curiosity is the honest signal, because it means the thing was nearly possible.

After trying something new, notice whether you want to go back. If the answer is no, look at whether it was too hard rather than concluding you dislike it. Adjust the size instead of abandoning the activity: a shorter route, an easier setting, a smaller piece. Difficulty is a dial, not a verdict.