Great 名言・格言 about losing a great teacher??

My school ロスト a fantastic teacher about a 月 ago, since it's クリスマス break, me and my 2 best フレンズ 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 によって the number of breaths we take, but によって 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 あなた oh, so much.