To-do lists deteriorate over time.

Maybe you’ve noticed. Have you ever looked at your to-do list and found it clogged with old tasks that are either unimportant, hopelessly vague, or no longer relevant? These tasks slow us down, make our lists long and unwieldy, and induce pangs of guilt when we’re trying to be productive.

Give yourself permission to delete these tasks. Scratch ‘em right off that list.

Purging old tasks is essential to maintaining any well-lubricated personal productivity system. The fact is, our priorities and circumstance change over time, and our to-do lists should reflect those changes.

I’ll admit that getting rid of old tasks is one of the hardest parts of maintaining a to-do list, but it’s also crucial to keeping our personal productivity systems running.

Here’s how I do it: When my to-do list has gotten out-of-hand, I look it over and remove any items that have been sitting there longer than a week. If this is too hard to do, I start a new list called “Things I deleted from my to-do list” and populate it with the old tasks from my to-do list. This creates a record of what I’ve deleted while still removing those tasks from my mental landscape. If a task simply must be done, I take a moment to figure out why I haven’t done it yet so I can address the problem and make sure I complete it within the next week.

Keep your to-do list lean and mean, and you’ll enjoy working from it much more. You don’t have to do everything Past You wanted to do.