The earliest piece of writing advice I was given was from a teacher I had in college called Dennis Bartel. He said: “If you want to write a novel, you have to sit on your ass.” I was 19 and thought: “Yeah, whatever dude, I’ll be writing my novel while I’m motorcycling across America and living this glorious bohemian lifestyle I’ve envisioned for myself.” What I ended up doing was going to graduate school, sitting on my ass and writing a novel.

I’ve recently turned 54 and I feel like I’ve finally learned to avoid a few fundamental mistakes in life. I have grey in my beard and in my hair and I think that makes people, especially on planes, treat me with more respect. I feel like a tiny bit of wisdom has begun to accrue. It’s like those sticks in the cotton candy machine that gather up all the cotton candy – I’ve had this bare stick for a while, but it’s finally starting to get some cotton candy on it.

Contempt is the place where marriages die. Once you get to that stage, I don’t know what can be done. Marriage takes work [Chabon is married to writer Ayelet Waldman] and realising the fact you’re working at it and it feels like work sometimes is not a bad thing. It doesn’t mean there’s something wrong because it’s hard. It’s supposed to be hard.

I have this thing called trypophobia which is a horror of small clusters of holes in circular objects. Like the inside of a lotus or kombucha. I get this physical shudder and the hair on the back of my neck stands up. I think maybe it has something to do with an evolutionary reflex to avoid swarming things. It’s triggered for me when someone drops their icy lolly on the ground and it’s covered in ants.

I can get angry, but typically it’s a low boil, more of a Clint Eastwood-style anger rather than a Danny DeVito outburst.

Usually you don’t know that the last time you see someone is going to be the last time you see them. If I could, I would go back into my own past and see people’s faces again that I haven’t seen in a really long time – my grandparents, people who are gone, childhood friends. I would like to go back and see my bedroom when I was a kid just for five minutes.

I have a socialist approach to my regrets: they’re all equal. But the one that feels irremediable is when my grandfather died while I was in Paris and I decided not to go to his funeral. I was 23. He was a really important figure to me, but I didn’t realise at the time. He had stepped in when my parents got divorced and my father went away. He was sort of my second father, I just hadn’t gotten to that kind of consciousness yet.

I’m an optimist to a ludicrous degree. I wake up every morning and launch the news app on my iPhone and think maybe the first thing I’m going to see is “Trump Dead of Cardiac Arrest”. I wake up every day full of hope that this will be the day that his taco bowls and bacon cheeseburgers finally get the best of him.

Chabon’s latest novel Moonglow is published by Fourth Estate at £18.99. To order a copy for £15, go to bookshop.theguardian.com