He told talkSPORT: "We went to West Ham on the opening day of the season and won with ten men so we started to look up. We then played QPR in our second game and played brilliantly and won 4-0. Everyone was buzzing. Then we had our first real test of the season playing Liverpool and we got beaten 3-0 at home. It's been up and down.
"We don't know how good we are or how good we can be but the last two results against Sunderland and West Brom have been very disappointing. They were two games we felt we should be winning, especially the Sunderland game, so it's confusing at the minute. We should be doing a lot better than we have done recently.
"After the QPR game I thought, 'wow, we're a really good team and we might have half a chance of doing something this season', but then we played Liverpool and it was a huge reality check for myself. I stood back and thought there is still a lot of work to be done for myself and the team."
The Lilywhites renew hostilities with Arsenal in tomorrow evening's North London derby at the Emirates Stadium.