What is a growth mindset not?
Improvements which may be achieved through a growth mindset are not unlimited. The growth mindset is not the belief that anyone can achieve anything if he or she just puts in effort. As people we are all limited in many ways. We cannot learn to fly without equipment whatever our mindset is. We are also, as individuals, limited in some unique ways. The growth mindset does not say that a colorblind person can learn to distinguish colors if only he puts in lots of effort.
A growth mindset also does not mean that we can stop aging. We all get older and eventually will die regardless of the degree to which have a growth mindset. A growth mindset may help us increase the chance of remaining vital at an old age but it can't prevent us from getting old. Also, our possibilities of growth decrease as we get older. A 50-year old can improve his athletics skills but hoping to win a gold medal at the 100 meters at the Olympics is unrealistic, no matter how effective and persistent he'll train.
What a growth mindset also is not, is being obsessively engaged in learning and improving. A growth mindset says that you can get better with effort, not that you should get better. A growth mindset does not imply that we all should aim for the top or that anyone should become great at anything. Even if you have a growth mindset, you will have to choose to not get better at a great number of things.
Nobody can practice all sports and play all musical instruments, for example. Getting good at something requires focus. Focus on one thing requires saying no to lots of other things. A growth mindset goes together well with making choices.There is an essential difference between the decision not to start playing tennis because, to your regret, you think you will never be able become any good at it, and the decision not to start playing tennis because you find other things more interesting or important to master.