“Listen to the mustn’ts, child. Listen to the don’ts. Listen to the shouldn’ts, the impossibles, the won’ts. Listen to the never haves, then listen close to me… Anything can happen, child. Anything can be.” – Shel Silverstein
Dr. Seuss has a lot of great ones. One of my favorites is by Robert Browning- “Grow old along with me, the best is yet to be.” The actual quote is longer, but this is the part that rhymes and that I see written most often.