The other day, I found myself at a large event in a posh garden where David Cameron was present. Being a polite sort of person, he smiled and mouthed some sort of greeting as we passed. And being an impolite sort of person, I ignored him and walked on.

When someone asked me why I’d been so rude, I explained that I was just being consistent. I’ve been very rude about Cameron in print over several years, so wouldn’t it be a bit hypocritical – craven, even – to be all smiley and polite in person?

My rudeness has taken many forms and has several causes. I thought that Cameron’s near-immediate desertion of his post after the Brexit referendum was irresponsibility on a historic scale, especially given his refusal to allow the civil service to prepare for the possibility of a Leave vote.

I thought the referendum itself was the product of Cameron’s hopeless and spineless management of his party dating back to his daft 2005 promise to pull the Tories out of the European People’s party bloc in the European parliament. It started a cycle where he would make a promise to eurosceptics that validated their complaints but which he then failed to deliver on – then sought to make amends by making an even bigger promise. He fed buns to a crocodile, which grew until it was big enough to take over the bakery.

And I thought that Cameron’s post-power antics with Lex Greensill were deeply shabby, the actions of a man who doesn’t feel that the little people’s rules apply to him.

I also have a rather more personal grievance against our former PM, but I’m not – quite – ready to write about that yet.

Overall then, I’m not David Cameron’s biggest fan, so being a bit rude to him in a garden felt like it made sense. It’s also been good copy: I’ve written several nasty columns about the man over the years, and yes, been paid for them.

But a couple of things have made me reflect on this since that moment of childish spite in the garden.

One is a conversation with someone at Alzheimer’s Research UK, where Cameron has been president since 2017. According to my friend there, he’s been extremely good for the charity, devoting a lot of time to supporting fundraising and influencing while never seeking credit or acclaim. In a world where some are very keen for you to know about their selfless work for good causes, that deserves a positive mention. And today’s headlines about a dementia treatment drug are just a reminder of how much that work matters.

The other thing that gives me pause is today’s date, the tenth anniversary of possibly the best thing the Cameron government did. On 17 July 2013, royal assent was given to the Marriage (Same Sex Couples) Act. For ten years now, gay couples have been able to get married.

Gay marriage quickly became one of those reforms that ends up a permanent fixture: no party would seriously contemplate its repeal

This is a good thing, as Cameron himself argued back then. It may have been mildly controversial at the time, but gay marriage quickly became one of those reforms that ends up a permanent fixture: no party would seriously contemplate its repeal. (See also: the ban on smoking indoors; London’s congestion charge).

There are some perfectly good arguments to be made that Cameron doesn’t deserve real credit on gay marriage. Some would claim Tories such as George Osborne and Boris Johnson were braver on gay equality. Others might suggest Nick Clegg and the Lib Dems pushed Cameron into it.

But none of that matters. The law passed on his watch. He was PM at the time, so just as he takes final responsibility for bad stuff that happened, so he gets the credit for good stuff. And letting same-sex couples get married was a good thing to do.

All of which is a reminder that life is complicated and no one is wholly good or wholly bad. David Cameron may be a shallow spiv who risked his country’s strategic and economic future on his own personal charms then ran away to make money when he failed, but he also did some good things for the world. Well done, Dave.