Doesn't matter how quick you are, everyone needs practice. Could be to get faster, more consistent, become more aware.... But everyone needs practice as every race is different!
Might be the same cars and track, but it's human opponents, their lines will change so your have to change! You can be the quickest hot lapper in the world, but if you are racing someone else, you have to take different lines, so keep practicing and just try to be mindful of others (Keep aware of where everyone is - look button come in very handy!)