Certain authors and novels, if you come across them at the right age, will change your life. Terry Pratchett was one of those authors for me, and while his recent death was long anticipated, due to the cruelty of early-onset Alzheimer’s, the news, when it came, proved just as gut-wrenching as the original announcement of his illness had been.

Already, there have been plenty of appreciations of the man and his work. It’s a mark of both the nature of the man and the talent of the author that someone who primarily wrote comedic fantasy touched as many people across as many fields as he did.

I never met Terry Pratchett—the closest I came was during one of his visits to Dublin, when I spotted him walking in College Green, heading from Trinity College to (presumably) a pub, surrounded by a gaggle of students and admirers. It would have been nice to have the chance to talk to him, but at that stage he’d been talking to me through his work for years.

Books like Good Omens, Small Gods and Pyramids reduced me to helpless giggling more than any since Douglas Adams’ Hitchhiker’s Guide to the Galaxy. (Another author and decent human being taken too soon.) Across the 40 books of the Discworld series, Pratchett mixed the deftest wordplay with humour both low and cutting and serious thoughts that stole upon you in the midst of the laughter and stuck around long after the jokes were done.

As a kid growing up in a Northern Ireland still caught up in the lunacy of the Troubles, Pratchett provided constant reassurance that there was a better humanity out there. That being decent to other human beings mattered most of all, that you ought to be suspicious of anyone or any organisation that would tell you what to think, that being curious, patient, and argumentative were all good things. Thoughts that I found it hard to express, even as I was working them out in my own head, I found reflected in his prose.

As an aspiring writer, the most important thing I learned from him was that it was possible to underlay fantasy and science fiction writing with serious topics without preaching to your audience. I learned as well that language was a game, one that you won if you brought a smile to your audience’s face, or just made them pause and consider for a moment.

As a human being, he was, like his collaborator Neil Gaiman, like Douglas Adams and Charles Darwin, one of those people it was possible to admire without having to look up to them. Possessed of immense talent that never overwhelmed his innately decent humanity, yet driven by an inner anger that allowed him to churn out books of breathtaking quality and wit year after year.

That same anger helped him to deal with the unfairness of his diagnosis. Deeming it “an embuggerance,” he continued to live his life even more fully than before, fighting on behalf of those suffering from Alzheimer’s and those who believed that they had a right to end a life that had become unbearable. His eloquent arguments in favour of the right to die in the manner of his own choosing revived a debate that is still going on.

Reading Pratchett and authors like him and growing up where I did and among my family and friends has led me to the belief that if we have a purpose in life, it’s to increase the amount of happiness in the world, both your own and that of those around you. Far more than the number of books he sold, the joy that his work and personality brought to so many is a marker of his success in life.

If I ever have any kids, I’ll enjoy sharing his books with them. And whether or not they turn out to be fans like me, I hope that some of the lessons that I’ve learned in reading his books will be the same lessons I share with them.