The England international shrugged off a shaky debut season to deliver a consistent and confident 2018/19 campaign.
"It is important people aren't thinking it [his form] was a one-season wonder," says Keane.
"You need to keep improving all the time.
"I am reaching the age where I will be in my prime in the next two or three years.
"I am only going to keep getting better, I think.
"I have always had the right attitude, the desire to keep learning and working hard every day.
"The manager [Silva] played a huge part [in Keane's upturn] when he came in.
"But the biggest thing was myself, mentally, wanting to prove people wrong and show them how good I could be.
"I want to play for England and to do that I have to put in top performances every week for Everton.
"I feel really comfortable for club and country now, and whenever I step on the pitch, I know I am capable of performing really well.
"I have to do that consistently and help my teams get good results."