"Know thyself," said the old philosopher, "improve thyself," saith the new. Our great object in time is not to waste our passions and gifts on the things external that we must leave behind, but that we cultivate within us all that we can carry into the eternal progress beyond.
Quotations (such as have point and lack triteness) from the great old authors are an act of reverence on the part of the quoter, and a blessing to a public grown superficial and external.
If both the past and the external world exist only in the mind, and if the mind itself is controllable – what then?
Look at what your idea of success would be. The more that you take in external motivators, the more it reduces your ultimate satisfaction because it doesn't come from inside.