When you study, make it a primary goal to engage the assumptions and arguments that undergird the ideas you engage. You don’t need to read other people’s works in order to merely have an opinion. You can form and hold opinions all by yourself. One of the main purposes of reading other people’s works is to force yourself to confront the logic behind a point of view that significantly differs from your own.
It’s not enough to merely agree or disagree. Critical reading is about being able to identify the following things: 1) What was the author’s main point? 2) What evidence did they offer for that point? 3) Were their arguments sound? 4) Why do you accept/reject their arguments?
Don’t just regurgitate what they said. Don’t just point out what you liked or disliked. Push yourself to engage at a higher level. If you like their position, can you come up with a better way of defending it? If you dislike their position, can you show where the errors are in their thinking? If you simply don’t think their ideas are applicable to your life, can you clarify your understanding of what kinds of ideas you actually need?
It’s good to get inspired, or fired up, or frustrated about what you’re reading. It’s even better when you can translate those visceral responses into an opportunity to increase your knowledge of self and improve your ability to analyze what makes ideas good or bad.