Corrupted keys and forgotten passphrases...
Here I discuss the consequences of lost private keys or passphrases used to protect these keys.
This must not happen!
Nobody can read or recover the passphrase or reconstruct a cryptological key! This is a security feature.
Backup your private keys and keep them on a safe place. You may backup single keys or the complete folder that holds the gnuPG key rings.
Write down your passphrases and keep them safe. Do not forget to note new passphrases if you have altered them.
You should deposit the enveloped passphrases and perhaps copies of your keys with a confidential person.
Be aware that events may happen that will destroy your memory.