Kante was speaking in a Chelsea documentary.
"I didn't always believe that I would become a professional footballer," said the Frenchman.
"When I was younger I played in the lower leagues, I failed quite a few trials at professional clubs.
"When I failed I watched the players in those academies and went home and told myself there was a lot of work to do.
"I worked twice as hard to keep up the hard work and maybe one day it would happen.
"I think those failures allowed me to build myself to become a professional player."