Students of Joanne Baron/D.W. Brown Studio in Malibu, California, were left stunned when the actor turned up unannounced at the ceremony, and gave a rousing commencement speech filled with humorous stories from his own career, reports nypost.com.
"It was one of the most inspiring speeches we've had. It was so much more than a lecture about what to do in an audition," a source present at the ceremony said.
The actor, who has given blockbusters like "Top Gun" and "Mission: Impossible", advised the students to make most of the available time and opportunities.
"He said that when you do finally get the chance of being in a movie, don't spend your time in the trailer," a source said.
"He said you need to experience everything on the movie; talk to everyone on the crew - the grips, everyone. Learn everything you can. You will never get that time back," the source added.