When reading a book with your finger, concentrating on a line requires you to cover the line underneath and ignore the line above. There is almost no way to go through the entire text at the same moment.
I believe the process of 'reading' someone operates in a similar manner.
You are never exactly where the other person is standing. In order to see how they see things, sometimes you have to stand inside them like a ghostly figure, aligning your position with theirs, matching your outlines completely. By merging with somebody's perspective, you need to instantly refuse the existence of your own.
The decision to surrender to whatever is, however it is, trusting, no matter what, but from our position, never having managed to see the whole picture, at first feels like a punch in the stomach, asking from ourselves to start feeling safe in unfamiliar territories. But what if we soon realise that it's the sweetest thing we've ever decided?