The keeping of to-do lists, with any regularity and for an appreciable length of time, becomes an exercise in time travel and tribal relations.
The to-do list is a time capsule, containing missives and pleas to your future selves. The action items are messages thrown across chasms which start as shallow ditches, but within minutes and mere hours widen into bottomless ravines.
The you of the present moment, if you have your wits and will about you, control a sphere of the world that is, at worst, several minutes in diameter, and at best, if you have good focus, hours, and if you are truly in the zone, a whole day. Beyond that, and certainly overnight, lies the chasm of the future. When looked at from a certain perspective, you die during the night. Fortunately, unless your heart actually stops beating, a fresh clone of you is created the next morning, and helpfully preloaded with (most of) the memories and personalities of the you that existed the day before. The same process is repeated the next day; these individuals, being born and dying anew each day, are the tribe of your future selves, closer than family.
The main question here is this: Why is it not trivially easy to carry out items on your own to-do list? And the answer is: Because the one writing the list, and the one carrying it out are two different people.
So, in order to get most anything done (unless it can be accomplished here and now), you get into the business of sending messages -- letters, emails, IMs, scribbles on bar napkins or pristine bulleted lists -- to your future selves, hoping that they'll find them, read them, hopefully understand what they mean, care enough about you, their ancestor, and finally be persuaded to actually carry out these tasks that you set them. They may remember you fondly, but they will be strangers in a subtle but real way.
Unless the illusion of continuity, the feeling that you are a single unbroken organism moving through time, is particularly strong in your mind, you must fully grasp your situation, and come to terms with the fact that you yourself cannot do much, but must rely on persuading your tribe of future selves to accomplish tasks for you.
The way you choose to carry out your campaign of persuasion depends on your personal style. You can get royal-authoritarian, and simply command them (are they not your temporal children?), assign punishments, or offer rewards for obeying your orders. You can use guilt, fear, and loathing ('send email to so-and so' has been on your to-do list for a year! for shame!). You can give them inspirational speeches, rally them like a politician. You can impose on their kindness as on the kindness of friends and family.
I keep using the word tribe, because essentially, in building up the discipline to consistently accomplish your tasks, you are setting up a culture (spread out in time instead of space, and consisting of your future selves rather than neighbors), a small village, a tribe. Customs and laws have to be set down, respected, enforced. If you're going the authoritarian route, the villagers have to obey their chief. If that's not in place, something else has to be -- your future selves have to at least like and respect their neighbors (predecessors and ancestors). It helps to establish customs and politenesses -- if you helped and obeyed your past selves, your future selves will likely respect you more, and will be more likely to help you in turn.
- To-Do Lists and Time Travel

HAUS-MATES FTMFW!
But of course our bribes and beatings are enforceable only by their intended recipients... So, really, all that sound and fury is just drama for our present mollification. :/
Yes, sleep is the great killer of to-do lists. In 1998 I wrote this, about a girl I had a short-lived crush on who was obsessed with Burning Man:
That segment on gauntlet thinking is right on! I've been struggling, internally, to put to words exactly that feeling (both re Burning Man, and trips and vacations in general). Thank you!