To be successful, be successful.
Hmmm. That one almost demands a Homeresque "D'oh!" be parked at the end to spike its inscrutable truth. On second thought, the only thing here that's obvious is that this opening thought's going to take a few more tries to fully flesh out.
Here's Sir Arthur Helps, from 1868: "Nothing succeeds like success." Getting warmer.
All right, with apologies, let's start again. This time, we'll go a few laps 'round the ol' philosophical cul-de-sac. After all, if you're going to contemplate the broader Moneygoround, then gathering one's thoughts aboard a conceptual merry-go-round may prove useful.
Ah -- this one might do it: Success feeds on itself, gathering more success as it rolls down success-covered hillsides, like a snowball increasing its size, collecting more and more snow around itself.
OK, one more time: After a bit more polish and elbow grease, the central thought final emerges: The more success one has experienced, the more likely it is that added successes will arrive, and continue to do so with increasing ease.