As soon as they recognize him, they can understand something that has already happened, something that they hadn't noticed at the time but now makes sense to them--"Were not our hearts burning within while he was talking to us about the Bible?"
It's night, they've had a long walk, it's after supper, and they decide to go back to Jerusalem right then, not the next day.
The recognition of the Lord has to be shared, and shared immediately.
In Jerusalem, they learned that the Lord had also appeared to Simon.
Note the repeat about how he had been made know to them in the breaking of the bread. We usually interpret this to be related to Holy Communion, but we may also want to think about we recognize Christ in our midst when we share those ordinary meals as well.