To idolize someone is to admire or revere someone excessively. Obviously “excessive” is a matter of perception. It is subjective. One person would feel that putting pictures of someone on your wall (like nearly every teenager does with their favorite celebrity) is excessive admiration. One might feel like that is a perfectly healthy form of appreciation. To admire something and to deeply respect something and to appreciate something is healthy. But there are some key ways that idolization can and does turn negative.