Most people don’t realize that they gain different benefits for doing things they like versus doing things that their Master commands. For example, in Milarepa’s case he had to work very hard carrying stones and building houses for seven years before his Master would impart any spiritual teachings to him, after which he was enlightened. You may think that carrying stones as Milarepa did hastens spiritual progress so you might also start carrying stones.
However, even if you kept doing that for seventy years it would be futile. Even until there were no more stones to be moved your karma wouldn’t be erased. But suppose your Master tells you to move a stone at two o’clock in the morning, and you faithfully follow the Master’s instructions and get up to move the stone. Although you can hardly keep your eyes open you still do it blissfully because you know: “Master is the most enlightened One. I’ve offered my body, mind and speech to Her. Whatever She tells me to do, I just do it. Whether they’re logical or not, I’ll still follow Master’s instructions.” If you can move that stone with such a blissful thought in mind, it will be much better than Milarepa moving stones for seven years!
However, most people don’t understand this logic. That’s why, although it’s very difficult to find a Master, it’s even more difficult to stay and follow the Master in spiritual cultivation once you’ve found Him. It’s hard to attain Buddhahood because most spiritual practitioners can’t axe their egos so they only attain the level of Arhat or a saint. The “ego” consists of the preconceived ideas and worldly concepts that we’ve collected over our lifetimes. We hold convictions about what’s good and bad and think we’ve learned everything we need to know because the world has given us enough education so there’s very little that a Master can teach us. This is where we go wrong.