You'd be hard-pressed, these days, to find a psychologist who doesn't think we'd be better off if we spent more time in nature. The problem, for those of us who live in cities and work at desks, is the "time" part: there never seems to be any. Whenever I make it into the hills for a couple of days, I'm so rejuvenated I swear I'll start doing it fortnightly. Then I don't. "Climb the mountains and hear their good tidings… the winds will blow their own freshness into you, and the storms their energy," wrote the naturalist John Muir, enticingly – but that's too rarely an option. Very well, say the wilderness evangelists: at least spend an hour a day in your local park. Because who doesn't have a spare hour a day – apart from, well, lots of people? The research testifying to the benefits of immersion in nature keeps piling up. But it's not much use if you never get around to the immersing.
The advice of etiquette experts on dealing with unwanted invitations, or overly demanding requests for favours, has always been the same: just say no. That may have been a useless mantra in the war on drugs, but in the war on relatives who want to stay for a fortnight, or colleagues trying to get you to do their work, the manners guru Emily Post's formulation – "I'm afraid that won't be possible" – remains the gold standard. Excuses merely invite negotiation. The comic retort has its place (Peter Cook: "Oh dear, I find I'm watching television that night"), and I'm fond of the tautological non-explanation ("I can't, because I'm unable to"). But these are variations on a theme: the best way to say no is to say no. Then shut up.
Can men and women ever be "just friends"? The correct answer is: "Yes, obviously, so why in God's name do magazine editors, authors of dating books and headline-seeking psychologists keep asking?" My evidence is as follows: one, I'm male (and heterosexual, as the question implies); two, a majority of my oldest and closest friends are female; three, the prospect of romantic involvement with them strikes me, in most cases, as absurd. Yet the "debate" rages on. The latest round came a few weeks back, following a study from the University of Wisconsin that showed, even Scientific American claimed, that men and women "can't be 'just friends'". What it really showed was that men – specifically undergrads, which seems relevant – were likelier than women to feel attracted to opposite-sex friends, and that this might have "potential negative consequence[s]". The death knell for platonic cross-sex friendships? Not even close.