Would a proper adult ignore the spilt milk under the fridge for weeks?

Would a proper adult take three years to post a solitary Christmas card?

Would a proper adult have decades-old underwear in active service?
Mike Gayle is nowhere near being a proper adult - even though his tenth wedding anniversary is looming; his second child is due any moment; and in less than twenty-four hours he is going to be officially closer to forty than he is to thirty.

Appalled by this lack of maturity, Mike draws up a To-Do list containing every single item he's been meaning to do but just keeps putting off...

He's got a lot of stuff that needs doing. But unlike previous To-Do lists, he promises himself that this one will actually get DONE. And along the way, Mike will learn stuff about life (323), love (999), friends (1004) and family (9) and finally work out what it means to be a grown up (846).