The Gaffer was speaking following today's opening day defeat at Bristol City.
Barnsley were caught out by a Bristol City side who came flying out of the blocks in the first half at Ashton Gate, scoring three goals inside 15 minutes.
Reds Head Coach, Paul Heckingbottom believes his side started off well enough, but that mistakes which led to the opening goal set off a difficult period where anything that could go wrong, did go wrong.
"There was nothing in it at the start," he said. "They've hit the bar, great save by Davo (Adam Davies) but then we've hit the bar ourselves but the turning point was obviously the first goal.
"From then on, that was what's fundamentally wrong from us today in the game, especially looking at the goals. Dealing with the long ball - they got in twice with that same ball. Then not stopping the cross, and the third goal letting them come inside, which is a big, big thing that we don't want.
"But we know where we're at. It is tough to take but we know where we want to be and how hard we'll have to work to get there. We were much better second half, we grew into the game and we've got a goal at the end. So we're going to get better.
"We have to. The Championship is unforgiving."
You can see Paul's interview in full over on iFollow.