关于爱情最悲哀的事情不仅是它不能永远持续，而且心碎很快就会被遗忘。

The pace of change will never be slower than it is today.

The ability to associate depends, in turn, on the degree to which communities share norms and values and are able to subordinate individual interests to those of larger groups.

"There's nothing that says you have to be happy all the time."