Recently, on my first trip to Australia, I finally tasted Vegemite. At the time, I didn't realise I was having a philosophically significant experience, but according to the American academic LA Paul, I was. She uses the example of Vegemite to illustrate something that seems obvious, but that's actually rather intriguing, about "phenomenal knowledge" – the knowledge of what it feels like to experience something. The intriguing point is this: you can obtain such knowledge only from experience. No matter how much information I might be given by others about what Vegemite tastes like, that information can never amount to experiencing the taste itself. By the way, Vegemite tastes a lot like Marmite. I know: major anticlimax.

Anyone born in the 70s to parents of an even slightly knit-your-own-muesli disposition must have encountered the horror of "non-competitive games". The intention was excellent – to show that vanquishing other people needn't be life's guiding value – but non-competitive games fall short in one crucial respect: they're no fun. (Sorry, Woodcraft Folk, but you know it's true.) Recently, by contrast, I played Gears Of War: Judgment on a friend's Xbox, performed atrociously and had a brilliant time.

An economist walks into a bar. This is a true story; it's 2002, the bar is the Lava Lounge in LA, and the economist is an academic named Glen Whitman. He gets chatting to a fellow patron and mentions his line of work. "So," asks the stranger, "what are the Two Things about economics?" "Huh?" Whitman replies, confused. "You know, the Two Things. For every subject, there are only two things you need to know. Everything else is the application of those two things, or just not important." Whitman thinks, then replies: "One: incentives matter. Two: there's no such thing as a free lunch." Which is arguably a pretty good summation of the whole of economics.

The narrator of Joseph O'Neill's 2008 novel Netherland, a banker who has lived in both London and New York, seems permanently torn between the two – not merely as places to live, but because they embody different approaches to life itself. In London, he observes, people older than 40 considered themselves "over the hill and entitled to an essentially retrospective idea of [life]", as if all the exciting stuff were behind them, whereas in New York "selfhood's hill always seemed to lie ahead, and to promise a glimpse of further, higher peaks". That makes New York sound more fun, but on closer inspection both are depressing. Would you rather feel your life is over, or that the real you remains out of reach? Maybe O'Neill's globe-hopping banker would have been happier in some less self-regarding world city: Brussels, say, where they have good beer and shellfish, and probably – I'm guessing here – less existential angst.

One of the great strengths of the English language is the number of ways it provides to describe people who annoy us. True, German has the word "Backpfeifengesicht" – "a face in need of a punch" – but English overwhelms us with options, thanks partly to its abundance of vulgarisms. If I call you a "wanker" I mean something subtly different from a "dickhead". (It can be hard to pinpoint these nuances without resort to further swearing, as demonstrated by users of urbandictionary.com, as they struggle to define a "prick": "An all around fucktard, dickweed, assrat bastard.") These differences aren't just a matter of intensity. We can presumably all agree that Simon Cowell is a bit of a tosser. But his success makes it hard to dismiss him as a fuckwit, while it's not clear he's guilty of the malice that would condemn him as a shit.

It's a fairly well-established fact, in political psychology, that leftwingers report lower levels of happiness than rightwingers. (This fact, you may have noticed, is self-reinforcing: learning of it makes leftwingers even gloomier.) What's much less clear is why. Conservatives like to argue that it's because the things they value – traditional families, faith, free markets – make people happiest. Liberals prefer to think conservatives are blinkered, clinging to an ideology that lets them avoid confronting life's grim truths; it's even been proposed that conservatism might be a mental illness. And there's an added complication: the social psychologists who study such questions, as the American academic Jonathan Haidt has complained, tend to lean left. But does that mean they are biased – or that, when you closely study the real world, you usually end up liberal? ("Reality has a well-known liberal bias" – Stephen Colbert.) It's all very murky – though if you're a liberal, like me, that's less of a problem, as studies suggest we might have more capacity for tolerating uncertainty. So there's that.