The Belgian goalkeeper, who is on loan at Atletico from Chelsea, has been one of the club's star performers this season in the race for the crown in Spain.
As it stands, Atletico sit top of the table, one point ahead of second-place Barcelona and three from third-place Real Madrid.
"The game against Athletic was tough but we did well, three points on a very difficult field. A lot of people thought that we couldn't have won," he told Onda Cero.
"San Mames is very difficult. I think it rocked the table. There are seven finals left, there's a lot left to be played. We take things game by game and that's the best way to approach it. We have very difficult matches ahead of us, the best is to go game by game, what we're doing is great.
"We're taking things game by game and we'll see where we end up. It would be a dream to win La Liga. We have our feet on the ground. We are humble. We're close, but we have a few games left, the best is to go step by step."
Courtois is expected to return to his parent club in the summer.