If your productivity system isn't one that you can trust to actually help you work, it's no good. In a recent post at the GTD blog, David Allen explains why it's so important for your productivity system to trustworthy, or you'll wind up putting more effort into the system than into the work you need to do.
For example, if your system only half-reminds you of the things you need to accomplish, and you have to remember the rest, it's not helping. If you spend more time managing your system than doing the things your system needs to tell you to do, it's not helping. He elaborates:
A beginner at the wheel of a car will have jerky, small movements. They are maintaining control, just at small increments of focus. Only as they learn to trust the car's responsiveness can they let go on that level, extend their horizon, and cruise at higher speeds more easily. Similarly, if you don't fully trust your personal systems, you are likely to be dedicating inappropriate and unnecessary mental attention to details and content, often with a resultant negative emotional component. You'll feel pulled, overwhelmed, and often like you're close to losing control. But you can't trust your system until it's trust-worthy. When is that? When you know you have captured all your commitments, clarified what you're intending to do about them, decided the actions you need to take about them, and have parked reminders of those actions in places that you know you'll look, where and when you need to.
Bottom line, when your system makes you feel comfortable and confident that your bases are covered, and it has a track record of actually helping you do your work without missing anything important, then it's worth your trust, and you can relax.
If you haven't found a system like that, maybe your existing one needs a tweak, or it's time to go back to basics and start with something a bit simpler.
Are You Micromanaging Your Mind? [GTD Blog]