When you entrust the system with your data under the pretext that the system can help you to better manage your life, the system invariably gains greater power over your life than you, yourself, gain over it.
If your life is better managed as a result, it is better managed towards the greater interests of the system. The system, with its massively networked super brain, is much better equipped to exploit an individual's personal data than any individual ever could hope to be.
When you casually input your data into the system's data store, you suffer an inevitable net loss of control over your own life. Your ability to exercise your own personal will over your life is diminished. The more information you allow the system to have about you, the more your personal will is displaced by the system's will.