If you like to confuse yourself, you can go ahead. My advice - just stick to KB. I know, I understand.. it happens. So many have felt like you. But, they gave up after some time. Finally, the result - they have wasted time! So, whatever it may be, just stick to KB and I am sure, you can score 100%! If you are completely new to Java, you better read HeadFirst Java first and then read KB. Else, go ahead with KB. Cheers!