The most exciting moments in mathematics are when you discover something that was hidden in plain sight.

If you lose or forget to bring a cable，adapter or charger，check with your hotel. Most hotels now have a drawer full of cables，adapters and chargers others have left behind，and probably have the one you are missing. You can often claim it after borrowing it.

Stories you read when you're the right age never quite leave you. You may forget who wrote them or what the story was called. Sometimes you'll forget precisely what happened, but if a story touches you it will stay with you, haunting the places in your mind that you rarely ever visit.

爱是脆弱的，你必须像对待生命体一样呵护它，否则它会消失。

Certification schemes are the grammar of responsible forestry—they give structure to our good intentions.