Don’t read this if you’ve not seen the final episode.

I’ve just finished watching the finale and what an unexpected finish. But yet it all makes perfect sense and we’d been given clues all along the way.

Don has spent the final series trying to find love and family life and been rebuffed at every turn. He gets divorced, Sterling Cooper leaves him, his dying wife rejects him and even the daughter of the woman who’s husband’s name he steals is too messed up to be family for him.

In the final episode, he only connects with his inner pain through a stranger’s dream – the tale of how an ordinary man thinks everyone else is having fun and he’s left on the fridge shelf locked away – like an unwanted product.

Don’s can’t find inner peace by chanting Om with the seekers on the clifftop, but he recognises how such moments move other people. His sudden smile is not soulful enlightenment, but for a marketing insight. It literally dawns on him, “Well this would make a great Coke ad”

He has failed at finding true happiness, so he goes back to selling it to other people.

He leaves the retreat, goes back to McCann and makes that Coca-Cola ad.

As Peggy says, he’s gone home.