We leave behind something of ourselves wherever we have been.
The only way to learn mathematics is to do mathematics.
一本书可以是一个朋友、一位老师和通往另一个世界的门。
变化是不可避免的，但成长是可选的。
Keep all your things visible in a hotel room， not in drawers， and all gathered into one spot. That way you’ll never leave anything behind. If you need to have something like a charger off to the side， place a couple of other large items next to it， because you are less likely to leave 3 items behind than just one.