The dedication to greatness doesn’t come because of the joy the achievement gives. It (joy/ happiness) is only an aftereffect. But it your ability to bear the pain and misery of work – is what brings greatness.
Yes! You should learn to love the pain – to love the misery. For it is in that work that you shape yourself, that you purify your soul.
Greatness has to be forged out of hard struggle and the bantering of the soul every time. But you will come out of the furnace as a pure metal.