Toure admits that even though they are sitting two points clear of Real Madrid in the Primera Division table, the after-effects of last season are taking their toll.
"It's much harder after winning six titles," said the Ivory Coast international ahead of Saturday's visit of in-form Malaga.
"We can't make any mistakes any more. Everybody thinks we're unbeatable, and that's not true. We are human and teams are fired up when they play us.
"There are so many games, and after what happened last year, it's not easy.
"But we are well prepared and focused on our objectives. However, both the league and Champions League are going to be very hard this time around.
"It will be difficult because they are a good team. We can't waste this chance at home because we need three points to stay on top of the table."