My problem is having two calendars - Google calendar for personal life and Outlook calendar at work. I have missed a couple of work functions because of it (not hugely important though). My lesson: if it is something truly important, I will go through the trouble of duplicating the work event on the Google calendar, setting the email reminders for when I need them. This way (given that I have an Android phone), I am always reminded when necessary. I have some events scheduled as far out as next year.

To keep track of what I am doing, I use pen and paper - supposedly that's the better method because it engages the hand-brain connection. Plus, the satisfaction that I derive from crossing out a "done" to-do simply cannot be matched by anything electronic.

As a general rule, cognitive tasks become easier naturally when we are well slept.