“Your mind is for having ideas, not holding them.” – David Allen
So much of the stress of modern life is worrying about what we think we need to do and worrying about forgetting what we think we need to do.
Putting aside whether or not many of the things we worry about (and do, for that matter) are worthy of our energy, we squander so much of our energy by not effectively capturing the thoughts that are important, but can’t be acted on immediately. That’s a fancy way of saying we waste energy by not writing stuff down.
The simple fact is we forget to do many things we think of, that we want to do. This leads to frustration with ourselves and stress when we have a thought and don’t write it down (or otherwise capture it).
When we have a workable system for capturing our important thoughts (tasks and otherwise… ), that we trust, stress melts away.
As David says above, our brains are for having thoughts, not holding them. To minimize, and perhaps eliminate, the stress (we feel about) keeping track of all the things you want/have to do, create a system for capturing those thoughts, that you trust. Both bits are critical: the system and the trusting of the system.