If someone is in the habit of agreeing all the time, their mind is like a garbage can, with whatever ideas just poured in. The least damaging result of this is confusion, conflicting ideas and random actions. There will be no constructive change. To disagree at once based on past experience automatically removes the possibility of learning anything new. This is called being a skeptic, one who can find a problem in any idea.
Skeptics never accomplish great things.
It is curious that we give such value to skeptics and critics, yet I have never seen a statue erected to one. The payoff of being a skeptic is to be safe, never wrong, and never the fool, and in extreme cases, being stuck. The third way is the only valid way to learn anything, testing an idea and assessing the results. I want you to consider all of the things that I present in that light. They are worth considering because of the insights and results to be gained.