You are making the huge mistake of assuming that if you hadn't given up when facing difficulty with the notation, the rest would have been easy, that you would have no trouble understanding the concepts!

Don't worry: you are not alone in making that huge mistake, plenty of people do. People that don't give up when confused about notation usually quickly learn that is the concepts and relations between them that require careful thought (and also, usually, that the notation was advantages they didn't realize when at first blush they found it confusing).