Great quotes about losing a great teacher??

My school lost a fantastic teacher about a maand ago, since it's christmas break, me and my 2 best vrienden are making a poster to remember him by..
we need great quotes, anything motivational to keep the students going after this hard time would be wonderful.

"Life is not measured door the number of breaths we take, but door the number of moments that take our breath away." <- we're using that as one, because that quote was at the sad sad funeral. (:

Thank u oh, so much.