Even if you're happy with the life you've chosen, you're still curious about the other options.

The unexamined life is not worth living.

The really important thing is not to live, but to live well. And to live well meant, along with more enjoyable things in life, to live according to your principles.

Beware the barrenness of a busy life.

In childhood be modest, in youth temperate, in adulthood just, and in old age prudent.

Life consists in penetrating the unknown, and fashioning our actions in accord with the new knowledge thus acquired.