Star Wars: The Last Jedi
Do you remember the scene in which Luke had to say goodbye to Leia Fisher in Star Wars: The Last Jedi? Before Mark Hamill walks away, he leaves a kiss on the forehead of Carrie Fisher. The actor said that this was actually a genuine gesture that he acted on at the right moment.

Star Wars: The Last Jedi
It Is Too Much For Him To Watch
As Mark Hamill was thinking about how Luke was biding her goodbye forever, he felt a surge of emotion. After all, he had been playing this character for a long time already. The actress died prior to the release of the film, which is the reason the actor could no longer watch this scene thanks to the strength of his emotions.

It Is Too Much For Him To Watch