Ben Garner feels his side have a lot to learn following a 3-1 reverse at Bolton Wanderers.
Scott Fraser fired the Addicks ahead after just three minutes with his third goal of the season, though strikes from Conor Bradley, Kieran Lee and George Johnston condemned Garner's men to a 3-1 defeat.
"It was a disappointing afternoon," the manager told CharltonTV. "We obviously start well, we go ahead and then we don't manage the next stage of the game well at all.
"I didn't think we showed enough bravery or enough courage to play our game. Defensively, we were too open and you can't come anywhere in League One and concede goals of the nature that we've done today.
"It was probably a little bit of a reality check in terms of where we are - looking at the depth of their squad and what they've got on the bench coming on. It proves we've got a long way to go and a lot of work to do on the training ground."
Asked what message he gave to the players during the interval, Garner said: "Basically to just do what we should have done from the start of the first half. We'd worked on it all week and for whatever reason we didn't do it. We didn't show enough bravery to play, we didn't have enough intensity in our game and we didn't commit to press enough.
"Whether it was the early goal, scoring that and thinking, 'we'll just sit here' or 'we'll change what we've worked on'... I just wanted a reaction at half-time and to just see what we're about," he continued.
"We did that at the start of the second half. There was a good response and we had some good opportunities, but for the chances we created we should have scored more than one goal away from home.
"To give them the third goal in the way that we did just killed the game. There's a lot to learn, a lot to improve and we need to do that quickly."