When a tree standing before or behind a house and projecting above or to the side of it is not sharply distinguished from the latter, it may serve to give it a very odd appearance.
These confusions of the mental image may arise even when only a short interval has elapsed.

In the case of many of the fleeting impressions that are only half recollected, this kind of error is very easy.

Thus, for example, I may have lent a book to a friend last week.

I really remember the act of lending it, but have forgotten the person.

But I am not aware of this.