It seems Sir Ian McKellen was mistaken for a beggar as he sat outside a theater in costume according to an article in the UK’s Telegraph.
In the article he said, “During the dress rehearsal of Godot, I crouched by the stage door of the Comedy Theatre, getting some air, my bowler hat at my feet (and) seeing an unkempt old man down on his luck, a passer-by said, ‘Need some help, brother?’ and put a dollar in my hat.” You can read the whole story and see a funny photo right here.