From Craig Townsend
Champion swimmers train every day and swim at meets because it is their OWN personal ambition. No one else's, just their own. Sure, it's also nice to win for other people, such as parents, coach or friends, but if these other people became the MAIN reason why they trained everyday, they simply would NOT succeed, it's as simple as that.
If these swimmers do achieve some results, it would only be through sacrificing something far more important, such as happiness in their own life. This is a major point, because regularly I see swimmers becoming disillusioned with their swimming because they feel that they are striving for goals which are not their own, but someone else's. Often these swimmers feel pressured to perform, and often feel 'guilty' at the very thought of changing their goals to something they might actually want (such as changing events, meets, or even having a break) - all because they feel emotionally responsible to keep someone else happy.
The bottom line is this - you cannot succeed unless you enjoy what you are doing. This is NOT to say that you have to enjoy every single moment (there'll always be some areas which may not be enjoyable!), but the overall reason why you get out of bed in the morning must be because you are happy with what you are doing. This is actually a major principle which applies to 'life' as well as swimming - you must either enjoy it, or find a way to enjoy it - if you wish to succeed. No one else's motivation will ever be enough to keep you going, you must have the motivation inside you already. All champions are self-motivated, driven people, they know what they want and they go after it - and they would never, ever bother trying to accomplish something that did not motivate them, not even if their best friend wanted them to do it. This is because they'd know that it would be a simple waste of their time and energy.
It's important to swim for yourself, and no-one else. Because this is only kind of motivation which will succeed, or be for your own benefit. Once again, it is always NICE to win for other people, but don't make them your focus - or it will steer you in the wrong direction. Always follow your heart and do what makes you happy, and you cannot go wrong.