"Before I arrived at Chelsea the club spent a lot and won a little," Mourinho told the News of the World. "After three years at Stamford Bridge I could say that the club spent less and won more, a lot more.
"That was my challenge and I find it hard to swallow that they say that Jose Mourinho didn't work to build success because he could buy it.
"I know what they say outside the Stamford Bridge walls: 'Mourinho had an easy job, because he only had to ask for a player and the Chelsea owner's chequebook did the rest'.
"I don't think so. Every penny spent on signing players brought more responsibility, because if I failed in my performance, the next day I would have everyone on top of me, calling me incompetent.
"It wasn't during my time that the great madness of expensive signings was committed which then brought no results, with the club running up debts, as players were brought left, right and centre, as if wins could be bought as an automatic right.
"In football, success can't be bought. Success is worked for, and anyone who doesn't understand that also doesn't understand the difficulties of modern football.
"Money helps, but only if it's applied with the right criteria. Otherwise, it's useless and only trips you up."