You'll get used to it. All my passwords are long (~20) strings of random alphanumeric characters. Initially, when I started using this system, I had doubts that I would be able to memorize them all, but after a while it got easy.

If you're really in need of some outside help, write it somewhere in rot13; since it's random, nobody can guess through the pattern of the letters that the rot13 version is not the actual password; a random string of letters and its rot13'd version are much the same for all practical purposes. And if you want some extra security and you're not worried about getting tangled in all your weird personalized decoding rules, write it backwards; write every number as ten minus that number; make all capitals lowercase letters and vice versa; add known short strings of characters at the beginning and/or at the end, etc. But I really don't recommend going down that route.