What did someone do that made you think they were really dumb?
What was something that someone did that made you think they were really damn stupid?
מה מישהו עשה שגרם לך לחשוב שהוא באמת מטומטם?
מה היה משהו שמישהו עשה שגרם לך לחשוב שהוא באמת טיפש?