There will come a time when everybody will know why, for what purpose, there is all this suffering, and there will be no more mysteries. But now we must live ... we must work, just work!
I will never forget that the only reason I'm standing here today is because somebody, somewhere stood up for me when it was risky. Stood up when it was hard. Stood up when it wasn't popular. And because that somebody stood up, a few more stood up. And then a few thousand stood up. And then a few million stood up. And standing up, with courage and clear purpose, they somehow managed to change the world.
It is worthwhile for one to make an effort to achieve happiness. Just as the purpose of a plant is to grow, so it is that the main purpose of every human being is to survive and to grow until death.