I have a friend who strives to do well at everything. Really. Everything. Maybe too much, in fact. There are times when I've watched her overthink to the point of being unable to perform at her best. Which only makes her more anxious about not doing her best. It happens a lot to a lot of folks. In our current culture; "if you're not moving forward you're backing up" and all the other cliches about doing "more" seem to be everywhere.
Nonsense. I'm a big believer in Pareto's Law, better known as The 80/20 Rule. Simply put, 80% of your results will come from 20% of your effort. This law was developed by Vilfredo Pareto, a botanist, when he discovered that 80% of his pea crop was produced by 20% of his plants. It holds true for everything; economics, all the physical sciences, art, music, business output, everything. An example: I want to play guitar. With 20% of the effort to become a master I can be 80% as good. That may sound like I'm not trying hard enough, not putting in a full effort. But for me it's plenty. I don't have time or the inclination to master guitar. I want to be able to strum the important chords and have some fun, not perform Ravel's Bolero at Carnegie Hall. 10,000 hours? Fuggedaboutit.
Sometimes good enough is both. Lighten up on yourself. Enjoy what you're doing and do some healthy comparison. Notice, with only a little ego, how you stack up to others. You're not the best Spanish speaker but you can hold a decent conversation while most people won't bother to learn "thank you" in any foreign language. (Some are even incapable of that in English).
Now, there's nothing wrong with wanting and working to be great at something. Just make sure it's worth it.
Seth Godin's post on this is, as is everything he does, brilliant.