You often mistake windmills for giants when you worry too much.
mistake windmills for giants
idiomTo perceive ordinary, nonthreatening objects or situations as significant dangers or adversaries, often due to an overly romantic, idealistic, or deluded worldview.
Origin
disputed originSomething to do with Don Quixote...
He is so eager to find a conspiracy that he constantly mistakes windmills for giants in his daily life.
By viewing every minor administrative change as a deliberate attack on his authority, the manager frequently mistakes windmills for giants.