Cech was one of the first senior players to welcome back Mourinho upon his appointment.
"I have been in this situation eight times saying I think this is the manager who will stay five years and we all hope it goes well, and a year later I was sitting here saying the same thing," he told the Daily Mail.
"Every manager who came in had ideas. They got three, four, five-year contracts and you hope the manager will be there, renew the contract, stay forever.
"Every time that happens you believe the manager will be the one that stays. Every time that happens, the other thing happened as well.
"This is how football goes and you never know. It all depends on circumstances, it all depends on the way the team will progress, the way results will go."