It's never to late to memorise a 60,000-word poem:
Pounding the treadmill in 1993, John Basinger, aged 58, decided to complement his physical exercise by memorising the 12 books, 10,565 lines and 60,000 words that comprise the Second Edition of John Milton's epic poem Paradise Lost. Nine years later he achieved his goal, performing the poem from memory over a three-day period, and since then he has recited the poem publicly on numerous occasions. When the psychologist John Seamon of Wesleyan University witnessed one of those performances in December 2008, he saw an irresistible research opportunity.
...Just how did JB manage to pull off this incredible feat? He studied for about one hour per day, reciting verses in seven-line chunks, consistent with Miller's magic number seven - the capacity of short-term, working memory. Added together, JB estimates that he devoted between 3000 to 4000 hours to learning the poem. Seamon's team interpret this commitment in terms of Ericsson's 'deliberate practice theory', in which thousands of hours of perfectionist, self-critical practice are required to achieve true expertise.
JB didn't use the mnemonic techniques favoured by memory champions, but neither, the researchers say, should we see his achievement as a 'demonstration of brute force, rote memorisation'. Rather it was clear that JB was 'deeply cognitively involved' in learning Milton's poem.Seamon, J., Punjabi, P., & Busch, E. (2010). Memorising Milton's Paradise Lost: A study of a septuagenarian exceptional memoriser. Memory, 18 (5), 498-503 DOI: 10.1080/09658211003781522
Basinger describes the experience in a way evocative of the ars memorativa, as a building he can enter and explore. Nine years is certainly short enough for a youth to learn such a poem, if it comprised the bulk of his formal education.
One might compare the case of a Muslim hafiz, who has memorized the entire Qur'an. The Qur'an has 114 chapters with a total of more than 6,000 verses, comprising some 80,000 words.