I am about to start my first year in college. I am not a class type student. I like going deep while studying myself and understanding the reasons, beauty behind these ideas. I have been looking for textbooks and realized there are many textbooks on the same subject. Of course some of them are highly recommended such as Spivak, Baby Rudin etc for analysis. I want to ask that if there are any significant differences between these top-level textbooks to understand the real theory and ideas? If I go with Baby Rudin and everything is clear for me, is reading one more top-level textbook a waste of time or could it really add my understanding more on this subject? Or should i continue studying another subjects? And also on the internet most people said that books like stewart and thomas' calculus are mostly for real life problems. Are books like them a requirement for me and are the problems on them rough? I want questions more like make me think and when I am able to solve I want to feel enlightened. Thank you for answers from now,I want to be a pure mathematician and I don't want to waste much time.