The answer you expected can make the actual answer difficult to hear.

Anticipation shapes hearing. Once you have rehearsed a likely reply, your attention starts matching what arrives against the version already in your head, and anything different registers as noise, a mistake or a refusal rather than as information. This is how people leave a conversation certain they were told something nobody said. Preparation helps you speak and quietly interferes with listening.

Before an important conversation, notice what you expect to hear and set it down deliberately. Afterwards, repeat back what you think was said and let them correct it. Being surprised usually means you were actually listening.