The veteran midfielder signed a new deal at the end of last season to put an end to any speculation about his future, all before the return of Mourinho was announced.
And with the 'Special One' at the helm, Lampard has revealed just how much of an impact the Portuguese coach had in his first spell with the club.
"He told me I was the best player in the world, but if you want to be recognised you need to win titles and medals," Lampard told The Sun.
"Whether he meant it or not I'm not sure, but he certainly knew how to get the best out of me, as I thought that I needed to prove this bloke right.
"So for him to come back, for me personally, is brilliant."
Mourinho has missed out on several of his more high profile targets this summer, with youngsters Andre Schurrle and Marco van Ginkel the only major acquisitions to the squad.
However, Lampard believes that Mourinho can help the new arrivals just as he did himself, and turn them into world class players.
"The good thing about signing young players is that they are for the future," Lampard added.
"And the manager's mentality will only help the young players.
"I believe there are exciting times coming ."