The friend is good at chemistry. So, he was able to explain his research to me without seeing anything. I can't believe that he has an ability to memorize such complicated chemical reactions.
On the other hand, I can't memorize even a structure of a molecule which I use most frequently.
Those who are familiar with chemistry say "Never memorize chemical reactions. You have to understand them."
But, it is difficult for me to find out what to understand.
