How about "you don't know any better and you don't realise there is anything to learn"?
In this case your* actions are still racist and you're making no effort to change them. If someone calls you out on your behaviour there's a chance you might realise you have unconscious prejudices and start trying to learn, moving from Unconscious to Ignorant on the Helo Scale. If everyone avoids mentioning it because it might make you nervous then you're being denied the opportunity to learn and instead go though life with everyone thinking of you as a bit of an arsehole.
* generic "you", not you personally.