I’ve seen this article It Is Better To Be Alone Than In The Wrong Company on several sites but I haven’t identified the source …
“Tell me who your best friends are and I will tell you who you are. If you run with wolves, you will learn how to howl. But if you associate with eagles, you will learn how to soar to great heights. A mirror reflects a mans face, but what he is really like is shown by the kind of friends he chooses.
The simple but true fact of life is that you become like those with whom you closely associate for the good and the bad. The less you associate with some people, the more your life will improve. Any time you tolerate mediocrity in others, it increases your mediocrity.
An important attribute in successful people is their impatience with negative thinking and negative acting people.”