Jose Mourinho has warned his critics he will have "many more years" as a manager.
The Manchester United boss took his first senior post in 2000 and has led huge clubs including Inter, Chelsea and Real Madrid during a glittering career.
Mourinho has the chance to win his second FA Cup when he faces his former club at Wembley on Saturday.
And the Portuguese, 55, says he still has the drive to be a success at the top level of football.
"It's my nature," Mourinho told BBC Sport. "I think if I was not a successful manager I'd be a successful something. A successful PE teacher, a successful... I don't know. I'd always be a person with drive with this nature.
"Probably the colour of my hair doesn't tell the truth. Maybe people think I am much older than I am. Maybe because I arrived in high level football very, very young maybe people think I am 66. I am not 66, I am 55.
"Even for the ones that don't like me so much, they are going to have me for many more years."