Memorization is a skill. And yes, it is more difficult for some of us than others. However, the more you do this, the better you become at it. I recently had a student complain, "Man, I spent 25 hours and can only play from memory the first 40 measures!" I responded, "That's GREAT! Imagine where you will be in 50 hours?"

Students often tell me how they are not good at memorizing music. All I can say to that is, "Yes, I understand, but how do you think we can become better?"

Trust me, the growth will be exponential.