From amongst the most amazing of those who memorised [knowledge] in our time was Ibn Taymiyyah; He would read a book only once and it would be etched in his mind (i.e. he would have memorised it).
There is nothing I have [ever] memorised and then [later] forgotten.
I have never said to a muhaddith ‘repeat it to me’ and nor have my ears ever heard anything except that it has settled upon my heart (i.e. I have memorised it).