In the movie Motorcycle Diaries, what do you think are some examples of what makes Ernesto and Alberto's friendship so strong?

Che is a risk-taker, and a bit of a hooligan graduate student. He and Alberto live the life of hobos and sometimes steal. Other times, they cause the kind of trouble that one would expect from two headstrong twenty-something college students. In the movie, Ernesto and Alberto balance each other out. Ernesto is pragmatic and blunt while Alberto is more diplomatic and stylish.