This is true of an errands or shopping list, or a daily to-do list.
It's also true of five-year plans and life goals.
Writing something down seems to convince my brain I'm serious about doing this so get on-board with it. It also has a way of moving things from the back-burner of my subconscious mind to the forefront of my active mind. So not only do I not forget about it, but I move toward accomplishing it.
At times all it takes is writing it down.
For those (3) of you interested in science and the brain, here's how that works:
The bottom of the brain stem contains a group of cells called the Reticular Activating System. Their job is sorting through the data incoming to your brain. It's main task is to send the urgent stuff to the active part of your brain, and send the non-urgent stuff to the subconscious. (This is what allows us moms to sleep through every little noise in the night except the whimper of our child down the hall.) Essentially, when you write something down - succinctly and with intention - you plug it into your Reticular Activating System. Then your brain starts to pay attention to that thing, labeling it "active status" and increasing the odds that you'll accomplish it.
If you skipped the slightly scientific section above, just know that writing is a way of directing your brain to pay attention to something until it is accomplished. All it takes is a couple of minutes, a piece of paper and a pen.
So, what is it you are wanting or needing to do? Go write it down!