Two-factor authentication exacerbates the problem. Now, instead of one thing that can go wrong causing you to lose your bitcoins (loss of the wallet), there are three things -- loss of the wallet, loss of the password, and loss of the second factor.
You're forgetting one thing, which is that you can have multiple copies of your wallet. Any risk in forgetting a password or losing your second factor can be mitigated by having an inaccessible wallet one a flash drive/CD in a safe. Also, although people forget passwords, they don't forget personal details. You can use a strong password for your day-to-day wallet encryption, but then on the backup flash drive, have your wallet also encrypted but with a slightly less-robust password that can be composed by you or only by someone who knows you very well. Put a text file on the flash drive with instructions on how to compose the password.
I'm not talking about vague preference questions that can change, such as "What is your favorite book?" but details such as the name of the bone that you broke when you were 15, the occupation of the person you were named after, the name of the house you lived in in college, whom your nickname is a reference to, etc.
No spaces, all lowercase, no grammatical articles.
I would only forget such things if I was shot in the head, but I'm certain that my family could put together the password if I died and they cooperated.