It's always going to be difficult motivating yourself to revise, but there's no-one better to get you in gear than Sir Ian McKellen shouting at you through a window. Or rather, Gandalf.
The Lord of the Rings actor was visiting Chew Valley School in Somerset, when he decided to share some words of wisdom with the students who had congregated outside the library to catch a glimpse of the star.
See Also..23 Pictures Of Truly Awesome Teachers