Concerning memorizing, I think there is a thread in the forum about ways to strengthen memory, I think it's this :
Ways To Strengthen One’s Memory
I can give you a tip about memorizing, I heared it from one experienced Sheikh :
"If you want to memorize the quran or any text, try to memorize it line by line (or aya by aya). For each line/aya do the forllowing :
1) just read it and try to understand it.
2) look at it deeply and concentrate in it, and try to see how it's written (the form of words, the order and the position of words.
3) keep looking at it (the line/aya) and take a profound breath in order to bring a maximum quantity of oxygen while you're concentrating.
4) don't look at the line/aya, and try to repeat it in your mind about three times.
after that (3 times) the text line/aya is completely memorized.
then repeat this method with all ayat/lines you have untill you memorize all the text."
And I want to tell you that your memory is not weak, you have a good memory but it needs activation. Memory is improved by exercice (like every organ in the body), It will be a little bit hard to memorize in the first time, but after 2 or 3 exercices, you'll be surprized how good your memory is.