Which you sync to the cloud using iCloud, and you've lost access to your computer because the drive failed and now you can't answer the question because you can't access iCloud to get the information back out :P
You should never rely on the 'cloud' as your only backup. You should always have a local backup as well. At least, while we are on the subject of ideal best practices for individuals :)
Then sync it to two devices so you have two factor verification ;)