GPG: "decryption failed: no secret key"

I'm new to GPG and am incapable of understanding cryptology. I'm trying to decrypt a message (that should be encrypted for me) and I'm getting the error:

Quote:

gpg: public key decryption failed: No secret key gpg: decryption failed: No secret key

My private key is listed under "gpg --list-secret-keys". pass works correctly, which suggests to me that there shouldn't be a problem.

Apologies for the n00b question. As I said, I don't understand any of this and can't begin to troubleshoot it on my own. Help greatly appreciated.