TeamData does not store a copy of your master password, so only you know it. In addition to gaining entry to your account, your Master Password is used to unlock (aka decrypt) the sensitive data in your vault.
Sensitive data is given an extra level of encryption that requires your master password to encrypt and decrypt. Sensitive data includes fields marked with a lock (usernames, passwords, account numbers, etc.) and files. Therefore, if you forget your master password, you may reset it, but any sensitive data in your account will be deleted since you no longer have the key to decrypt it.