Hold your standard, compassionately
If you want to be good at anything, you have to set your own standard and continually raise it. If you allow others to set your standard, they can lower it to zero or set it impossibly high. You compete with yourself first and foremost, to better yourself.
If you want to be happy at all, on the other hand, you have to be self-compassionate. You have to be okay with yourself and at peace with yourself in the present moment.
If you strive for excellence, you can burn out.
If you want to be happy, you can become complacent.
Both these mistakes are costly.
As you navigate life, much like a car navigates terrain, you want to aim for a smooth ride. Slow down before a turn to speed up on a straightaway.
Be self-compassionate and at peace when you need to rest, so that you can pursue excellence tomorrow.