For quite a long period in my 20s I would buy very worthy intellectual non-fiction books (based on reviews or recommendations) and then struggle to make headway with them. In retrospect, I think I was just usually too tired from work and life to have the mental energy to focus.
I then read an article by (IIRC) Irvine Welsh, the nub of which was ‘just read something’ - and reading fiction rather than non-fiction, and even trashy fiction rather than worthy fiction, was immeasurably better than not reading at all.
It was like I was given permission to not have to try and be intellectual and serious: (or pretentious?) and I’ve never looked back. Amongst many others, and to my surprise, I found I enjoy (what one might call) mid-level science-fiction and have happily worked through quite a lot now.