Who knows why, possibly from what you have explained, that might be the reasons.
You sound ready for it now, that's for sure. I remember buying a book in 2008 thinking I'll read it, but it was
way out of my depth back then, and only last year I stumbled across it just like you did in an old box, nearly 10 years later.
I was ready for it, and it touched me.
You are called to read it, so go read it, something profound might come out of it