To pay them too much honor.

Apart from this, what goes on in other people's consciousness is, as such, a matter of indifference to us; and in time we get really indifferent to it, when we come to see how superficial and futile are most people's thoughts, how narrow their ideas, how mean their sentiments, how perverse their opinions, and how much of error there is in most of them; when we learn by experience with what depreciation a man will speak of his fellow, when he is not obliged to fear him, or thinks that what he says will not come to his ears. And if ever we have had an opportunity of seeing how the greatest of men will meet with nothing but slight from half-a-dozen blockheads, we shall understand that to lay great value upon what other people say is to pay them too much honor.

The Essays of Arthur Schopenhauer - The Wisdom of Life by Arthur Schopenhauer