How does the idea "ignorance in bliss" fit into Kant's argument?

Immanuel Kant expressed more than once that Reason does not lead to happiness, but rather takes away from it. For example, in his Groundwork of the Metaphysics of Morals, he says:

"In actual fact too we find that the more a cultivated reason concerns itself with the aim of enjoying life and happiness, the farther does man get away from true contentment."

He explains that Reason sometimes goes against our impulses, and that satisfying those impulses is what brings happiness. The more an individual is aware of their moral duties and what to do to achieve them, the more their reason is in conflict with their happiness. Therefore, "ignorance is bliss". However, he also believed that the goal of Reason is not happiness; the purpose of human life to him was to be morally good, and that is what Reason was for.