The man I see for the first time may be so neutral to me that I pass him unregarded.

But let him return after I have once remarked him, or let him resemble a man whom I know, or let him give me some reason to observe, fear, revere, think of him in any way, then he is a positive factor in my stream.

He has been taken up into the flow of my mental life, and he henceforth contributes something to it.
For example, a little child, after learning to draw a man's face, with two eyes, the nose and mouth, and one ear on each side, will afterward, when told to draw a profile, still put in two eyes and affix an ear to each side.

The drift of mental habit tells on the new result and he can not escape it.
He will still put in the two eyes and two ears when he has before him a copy showing only one ear and neither eye.
In all such cases the new is said to be Assimilated to the old.

The customary figure for man in the child's memory assimilates the materials of the new copy set before him.
Now this tendency is universal.