The Reds secured their first win of the current campaign in the derby clash with Huddersfield at Oakwell after taking just one point from their previous four league encounters, while they were dumped out of the Capital One Cup by Southampton last week.
However, O'Brien feels it is only a matter of time before David Flitcroft's side show the collective spirit that saw them lose only one of their last 11 league games last season.
"I think everyone expected us to come charging out of the blocks, really firing, but it's a different season," O'Brien told Press Association Sport.
"But we have a gameplan and we trust it. We trust what the manager's trying to do, it's just about putting it into practice and learning from the mistakes we've been making.
"I think if the fans stick with us and don't get frustrated with us during games, that's important to us.
"We've had some new guys come into the squad and it's important they learn quickly what we're all about.
"We need to gel with them and they need to get to know us better. Pre-season was great, especially in Spain and a few of the newer lads came out of their shell. It takes time, but we're getting up to speed with each other."