'Idea' in the Bible

After tasting the water which had now become wine, the master of the feast (having no idea where it came from, though it was clear to the servants who took the water out) sent for the newly-married man,

But He told them, “I have food to eat that you do not know about.”

Jesus, however, was talking of his death: but they had the idea that he was talking about taking rest in sleep.

And then looking round, she saw Jesus there, but had no idea that it was Jesus.