Like, its not that far of a leap.
I can see him up until 3 am in the common room with his potted ink and quill scratching notes in the margins of all his essays, curly hair wild and everywhere and only getting worse as he pulls a knit vest over his head and redoes his tie through refined muscle memory. I can see him thumbing through Shakespeare and the Odyssey, obsessing to Oliver Wood levels over history and knowledge, consuming his breakfast at the speed of light as he pours over philosophy, just so he can crawl up the tree in the garden to continue his reading there. I can see him scribbling notebooks upon notebooks full of poetry and lyrics and snippets of story never to be written with character sketches so fleshed out they seem to escape the page. I can see him wandering through the graveyard of Ottery St Catchpole and jotting down the best names and anything else that comes to mind as he mentally prepares his plans for the night (a date with a cup of cocoa and a typewriter he saved 11 years of loose change for).
I can see him wearing vests and trench coats and slacks and ties and blazers (can you see him ever wearing jeans or a t-shirt?).
Imagine him trying to rush through an entire chapter just as the sun breaks the horizon because his last candle is burning out again and its 4 am and he has work tomorrow but ill read just one more chapter.....