Arsene Wenger knows Arsenal will finish the season empty handed if they continue to falter when it matters most.
Wenger's team looked set to go top of the Premier League after leading 2-0 at half-time against archrivals Tottenham at the Emirates Stadium on Saturday.
Arsenal were stunned by a second-half comeback from Spurs, who produced a remarkable 3-2 win to record their first away win over their neighbours since 1993.
There was some consolation for the Gunners in the shape of Chelsea's 1-0 defeat away to Birmingham City, but the Frenchman knows his young team need to mature fast if they are to claim major honours.
"It is painful, but more because we had an opportunity to go top of the league that we did not take, and a mature team, you want them to do it,'' said Wenger. "That is what hurts the most, because that is what is needed if you want to be successful and win trophies. We delivered quite a good game and created many chances.
"What is much more difficult to understand is that we lack some basic concentration on facts in the game where you can be punished. When you want to win, that cannot happen."
The 61-year-old was disappointed his team could not convert more of the chances they fashioned and he conceded their home form has become a problem.
"When you look at the run of the game, what we created and what Tottenham created, you are a bit speechless we lost," he said.
"But we lost our focus, were punished on that and made some basic mistakes. At 2-0 up, it looked too easy and we eased a bit off. We certainly have a problem to sort out at home. It is a shame because overall we had quite a good game, one of the best we have played recently and were not rewarded."