head knowledge vs. heart knowledge

At that time Jesus said in reply, "I give praise to you, Father, Lord of heaven and earth, for although you have hidden these things from the wise and the learned you have revealed them to the childlike." Matthew 11:25

the visiting monsignor had a wonderful homily at mass on wednesday and i was just bold enough to ask him if i could have a copy of his "cheat sheet." of course, he said "NO!!" and then handed it to me (he is a humorous soul...)

the gist was as follows:

we can know a lot about ourselves
but not know ourselves.

it's the same with knowing God.
we can know a lot about God,
but not know God.

Jesus had this in mind when He praised his Father for revealing to the unlearned what He had hidden from the learned.

Knowing about God is an activity of the head.
Knowing God is an activity of the heart.

This raises a question: How does head knowledge differ from heart knowledge?

Knowing God is not so much a question of opening a book and reading about God, but opening the heart and loving God.