Today in the Church calendar is the day we reflect and remember Thomas a Kempis (1380-1471). He was best known for his book The Imitation of Christ.
Upon doing some reading of his works, I found a few quotes that would be decent life mottos.
"If, however, you seek Jesus in all things, you will surely find Him."
"If thou wilt receive profit, read with humility, simplicity, and faith, and seek not any time the fame of being learned."
"In angello cum libello (In a little corner with a little book)."
"In omnibus requiem quaesivi, sed non inveni, nisi, in hoexkens ende boexkens (I have sought everywhere for peace but I have found it not save in nooks and in books)."