At New Year, in preparation for my fortieth birthday this month, my wife gave me a list of forty challenges I need to complete before I turn forty. Some of them were easy (eat a food you hate, give blood, go to a zoo); some were harder (learn a new language, learn a new instrument, give up technology for a week); and some were impossible and therefore remain incomplete (lose 40lbs, do a 40-hour sponsored silence, learn to ballroom dance).

One of them is to make a list of forty things I’ve achieved in my life. I thought it’d be pretty simple because in my mind I’m someone who’s achieved a lot, but I actually really struggled with it, not least because of how to define what counts as an achievement. Is it a one-off event, like winning an award, or is it something ongoing, like a lifestyle? Is meeting somebody famous an achievement, or is making a connection with a stranger more noteworthy?

It really makes you think about yourself, and what you value, and what is important to you. As someone with depression and autism and social phobia, people tell me just getting out of bed in the morning is an achievement, but it’s hardly notable to do something that virtually every single person on the planet does on a daily basis. You can’t exactly brag about not lounging around in bed all day.

And that is how I’ve defined an achievement: something you can brag about. Or, rather, something you’re proud of that you’d want people to know about if you’re forced to do one of those ‘tell the group something interesting about you’ kind of things.

So here it goes. Forty things I’ve achieved in my forty years:

1. I managed to convince someone to marry me.
2. I had a non-fiction book published.
3. I have the courage to wear my cowboy hat in public, even if I get funny looks.
4. I sailed across the Atlantic as a crewmember on a tall ship.
5. I was interviewed on a BBC TV documentary about rescuing two Trans-Atlantic rowers while on the tall ship.
6. I taught myself to play the guitar.
7. I recorded three EPs and performed multiple gigs as lead guitarist and vocalist in various rock and metal bands.
8. I spent six months as a care assistant in an old people’s home and four weeks as a student nurse on an infection control ward.
9. I have given numerous speeches to educate people about autism.
10. I got a Diploma of Higher Education, two Bachelor Degrees and a Master’s Degree, and achieved distinctions for all of them.
11. I have two children, and in four years I haven’t killed them!
12. I have written eight novels and am still plugging away despite more than 300 rejections.
13. I travelled alone across the USA from the Atlantic to the Pacific through 23 States on 32 Greyhound buses.
14. I have been to the top of the Leaning Tower of Pisa, St Peter’s Basilica, the Eiffel Tower, the Empire State Building, the Space Needle, the Sky Tower and the Shard.
15. I worked for Prince Edward at his production company.
16. I qualified as a PADI Advanced Open Water scuba diver, making dives to 100ft and at night.
17. I dived with sea lions.
18. I have tried waterskiing, windsurfing, paddle boarding, bodyboarding, canoeing, kayaking and canyoneering.
19. I’ve made two static-line parachute jumps.
20. I made an iron bottle opener and a candlestick in a blacksmith’s forge.
21. I spoke to James Cameron about the movie Aliens.
22. I’ve done two bungee jumps.
23. I sold a painting to the mayor of Christchurch.
24. I caught a 50lb conger eel.
25. I made a 4,200 piece model of the German battleship Bismarck.
26. I was interviewed live on BBC radio about said model.
27. I created and maintained a blog for four years.
28. I’ve tended to injured pigeons, owls, sparrowhawks, hedgehogs and a deer.
29. I did a 140-ft abseil.
30. I’ve made 47 blood donations.
31. I spent three months travelling alone around New Zealand.
32. I walked eighteen miles around Auckland without stopping.
33. I spent three days trekking alone around the wilderness of Stewart Island.
34. I’ve tried archery, pistol-shooting, rifle-shooting, clay pigeon-shooting, fencing and karate.
35. I’ve climbed Mt. Snowdon in Wales, and Mt. Roy (Roy’s Peak), Ben Lomond and Avalanche Peak in New Zealand.
36. I worked as a 999 call-taker and radio operator for Thames Valley Police.
37. I did a falconry day flying owls, hawks and a bald eagle.
38. I won four consecutive short story competitions in a writing magazine.
39. I’ve read more than 1000 books, including all six Jane Austens, Watchmen, Lord of the Rings and It, and seen more than 1000 movies, including all six Jane Austens, Watchmen, Lord of the Rings, and It.
40. I made it to forty when I didn’t think I’d make it out of my teens.

It’s actually quite beneficial to do a list like this, if only to take stock of your life. It’s a sobering realisation that the majority of my ‘achievements’, on closer inspection, seem rather insular and self-indulgent. The one of which I’m most proud is that I’ve made 47 blood donations, sacrificing my time and comfort to help others. And look at what’s missing from my list – being a good husband; being a good father; being a good friend. Why aren’t they there? Because I’m none of those things.

Maybe I should make a new list: things I want to achieve.

1. Being there for a friend in need.
2. Apologising to my wife and taking the blame even when it’s not my fault
3. Letting the kids be kids without getting annoyed with them.
4. Accepting that this is my life.
5. Learning to enjoy living in the moment.

That seems far more positive. If I manage to achieve these by the time I’m 41, we’ll all be in a better place.