You don’t want to be selfish right? But you also are the (only?) person in charge of developing yourself, so your focus should be you.
So how do you balance these two, focusing on yourself, to develop yourself, and focusing on others to help them develop and live better lives.
Of course like anything else in life, it will be a seesaw, sometimes you focus more on yourself, and sometimes on others. And try to find the optimums balance at each time, given the circumstances and your abilities.
It’s not easy, but that’s life.