This depends on how good you are at recognise this condition, how well equipped are to help others and how intelligent the other person is.
Somebody said that you do not need to learn how to love, you just take out of your way everything that is stopping you to do it.
In a way, it is the same with intelligent, bright people self limiting themselves by an imposter syndrome. All the potential for a happy fulfilled life is there. You just need to recognise the problem, to become aware of the condition and just leave it behind.
This is not easy. Sometimes can be a lifetime struggle to conquer the imposter syndrome. But it is totally worth it. Once you did it, you are like a legendary Phoenix, ready to fly and reach your full potential. You were stagnant only because you chose to be. And the self sabotage for an intelligent person is so subtle that you cannot even see it. And very original also.
So, once you get over it, you start to see it around, to recognise it. All this self defeating attitude, all this limiting behaviour. And you know that others can thrive, can achieve greatness. But you are not able to change them.
That is unbearable.
To be able to change yourself but not to help others that are going through the same thing. But you are bright. You can learn. And one day you can become good enough in order to do it.
Short story, this is the reason behind why every genius chose to help others like them.