The dictionary defines ideas as am image of an external object, formed by the mind. Another definition is a notion, thought, impression, conception, or anything that is a product of your intellect, memory, and imagination. The word comes from the Greek and Latin meaning to see. Therefore, your ideas stem from your thinking processes and may not be reality. Ideas are good when it offers you the ability to see things from different perspectives.
Ideas are bad when they are distortions of reality. Since ideas are subjective, and they are as numerous as there are people. You should use this special human attribute to explore all possibilities. When you do this, you develop an effective worldview. Letting your mind watch thru many windows allows you to see many horizons. This will provide a wide range of interest, which will expand your understanding of human nature.
It does not mean that your ideas cannot change reality. The road between ideas and reality frequently take many twists and turns. Never shy away from the journey of using ideas to make things better. Never allow a setback or criticism to distract you from trying to improve your world. It takes many ideas to change the world. Change is essential to promote the common good.