I think there's some good evidence that our first impressions about people do tend to be pretty accurate.

Not always, which is why it's always right to hold off and be prepared to correct them, but as a rule of thumb I think we very probably find you have much the same kind of judgement about what someone is like after we've known them as we had when we first met them.

Of course we might have changed ourselves in the meantime - and we may have learned additional aspects of the person that changes things as well.