SELF-CONTROL LEADS TO ONE'S GOAL
Na hi etehi yanehi gaccheyya agatam disam
Yatha' ttana sudantena danto dantena gacchati.
Indeed, not by any means of transport (such as elephants and horses) can one go to the place one has never been before (i.e. Nibbana);
but by thoroughly taming oneself, the tamed one can get to that place (i.e. Nibbana) 
On one occasion, some bhikkhus saw an elephant trainer and his elephant on the bank of a river. As the trainer was finding it difficult to control the elephant, one of the bhikkhus, who had been an elephant trainer explained to the other bhikkhus how it could be easily handled. The elephant trainer hearing him, followed the instructions of the bhikkhu, and the elephant was quickly subdued. When the bhikkhus related the incident to the Buddha, he advised the bhikkhu, 'My son, you are still far away from Perfection, you should devote yourself to spiritual development.You cannot gain nibbanic bliss by taming elephants.*Only one who has tamed himself can experience the bliss supreme.'
*The Buddha here was not admonishing the bhikkhu for having given service, but he was admonishing him not to forget the ultimate goal of one who has renounced the world: to free the mind from all defilements and distractions.