Shakyamuni Buddha, even when he was a trainee on the path, was solely concerned in both thought and action with others' welfare. Whenever he found an opportunity to work for others, no matter what difficulties he faced, he was never discouraged. He never hated obstacles and hardships encountered on the way. Instead, the difficult situations facilitated his being more courageous and determined to accomplish others' welfare. Just because he was so determined to work for others in the past, even as a trainee on the path, it is needless to say how much more it is so with him now as a completely enlightened person.
As the saying goes, "A past life story of a teacher is an enlightening practice for posterity."
--from Generous Wisdom: Commentaries of His Holiness the Dalai Lama XIV on the Jatakamala Garland of Birth Stories translated by Tenzin Dorjee, edited by Dexter Roberts