I am a high school student who will be entering collagecollege in one and a half year (It is so long though).
For me, Mathematics quiteprimarily means Number Theory. My interest in Number Theory always motivatemotivates me to go and take a look at those wiki articles which are not really discussed in classic or even modern books.
For instance, while studying about prime numbers, I found many things not specifically discussed in books. Some of them are Legendre conjecture, Prime gaps, Mills constant etc. I am baffled that shouldconfused whether I should keep studying these things which authors don't dare to discuss or should follow the patterns of books instead.
For your kind information, I would mention that I frequently use NZM along with G.H H.Hardy's Introduction to number theory Hardy's Introduction to Number Theory
sometimes. For problems, I often do U CUC Berkeley's online assignments.