The Underappreciated Problem of Negativity.
I define negativity as any statement, action, thought, or feeling that has a negative quality to it.
When you read that definition, you probably thought, "Gee, what a stupid, trite, tautological definition. Any monkey with a typewriter could have come up with that." Your reaction was essentially a negative reaction and an example of exactly what I'm talking about. To remedy this, you must Practice Pure Positivity.
You must practice positivity in a positive manner, not in a negative manner. If you say, "I must eliminate all negativity from my thoughts," you are practicing positivity in a negative manner, which is bad. Instead, tell yourself, "I will have exclusively positive thoughts."