[tzs]

How often have you had information stolen off a credit card, passport, driver's license, insurance card, or other item with sensitive information printed on it that you routinely carry around in your wallet?

For most people, the answer is "never".

We are actually quite good at safely keeping secrets on paper in our wallets, and so generally writing down a password and keeping it there is fine, especially if the choice is between doing that with a strong password or using a weak password that you memorize.

[mamon]

Plus, people usually have a better memory that they give themselves credit for. With reasonably short random password (say, 10-12 chars, uppercase, lowercase, digits) that you use often, you will memorize it after a week, at which point you can simply destroy post-it note you carried in your wallet.

[ClassyJacket]

Plus if your wallet gets stolen, you will know someone potentially has your password, and change it.