Might I at least suggest using an easy-to-execute algorithm that you can apply to your note to turn it into a real password? There are many options, from adding a prefix, a suffix, adding a small integer to every number, or some combination of these. This, I think, is about as secure as you can get since a targeted attack would just install a keylogger and be done.
Even with an algorithm, you're still relying on human memory. As Schneier and other have been recommending for a long time, write down your passwords. People already understand some amount of physical security, which is knowledge that can can utilized for password storage.
As long as human memory is the weakest link, password strength will always be de facto limited to the amount of entropy that a human can reasonably memorize. Unfortunately, brute-force password cracking capabilities flew past that limit a long time ago.
My last work sent around a cardboard triangle "stand" thing which was supposed to remind us all about how much we loved working there and how important such and such policies were. So my password was set as the first 3 letters of the first 3 lines (inc capitalisation) followed by a fairly standard & [incrementing number]. It was written down right next to my computer for the first two weeks whilst I learnt it and then every other password was just a derivation of it.
