Maybe training your critical thoughts on mundane things helps to understand less mundane things, and give one the good habit of not letting alien ideas settle i

Maybe training your critical thoughts on mundane things helps to understand less mundane things, and give one the good habit of not letting alien ideas settle in unchallenged? Like gym for the mind? Ignorance is no more bliss than physical weakness is comfort. Also, isn't critical thinking synonymous with forming one's own opinions? If most of our ideas and opinions are not really ours, then really, who are we?