Young, Bright and on the Right, BBC2, ThursdayThe Girl Who Became Three Boys, Channel 4, Tuesday

A Tory boy elicits sympathy and a girl's gender fraud makes Shakespeare more plausible

So far, the only good thing anyone has had to say about turning 30, which I did yesterday, and which I've been dreading all year, is that I will now "know who I am". You spend your teens angsting about being cool and getting laid, then your twenties are about repaying debt and getting a job. By 30, apparently you know what you want, and people even start taking you seriously. We'll see.

Then I watched Young, Bright and on the Right, and realised it's all true. This was a documentary that followed two teenage Tories as they grease their way up the political poles at Oxford and Cambridge. Harry Enfield couldn't have written it better. Joe Cooke wears double-breasted suits and has Maggie Thatcher on his wall. Chris Monk has been a Tory since he was five, and, if you close your eyes, actually sounds like Tory Boy.

It was all set to be a classic fly-on-the-wall piss-take of two aspirational Thatcherites. It even opened with Monk apparently predicting the damage it would inflict: "While at 19, you're not old enough to make a political career, you're certainly old enough to break a political career." Sure enough, it was painfully funny, especially if you know that world: the scones, the waistcoats, the endless "nid-nodding over port", as Harold Acton summarised Evelyn Waugh's first novel.

But in between laughing and cringing, I found myself crying. For the story of Joe Cooke was more Dickens than Waugh: the son of a convict, Cooke didn't speak until he was five, and was picked on by bullies at his Yorkshire comp. One day, he looked round and thought, "I know I'm better than this", so he worked his guts out and got into Oxford. "Why shouldn't I get what I want to get?" he says. "The Conservative ideal is that where you are born should not determine where you end up." All very William Hague.

And yet, even in 2012, the old snobberies run deep, and in a tearful moment, Cooke admits that reinventing himself has come at a price. "You put on such a front down here, that as soon as you delve a bit, the façade crumbles. When I came here, I was one of only 25 pupils entitled to free meals. I got laughed at for having a Yorkshire accent, let alone the truth." The truth being that his father went to prison when Cooke was four."

The Girl Who Became Three Boys was another fascinating story of youthful fantasies gone wrong, albeit of a more tabloid nature. Gemma Barker is a teenage girl who invented three Facebook identities for teenage boys, with which she seduced two female friends. Astonishingly, by communicating mostly by social media, and by always wearing a hat when they met, she got both girls into bed without them realising she was their friend. One of them only twigged on spotting a dildo in his/her bag. Barker is now serving a 20-month prison sentence, though the psychiatrist's report found she had no known personality disorder.

I've always thought the most impluausible thing about Shakespeare is how characters swap gender without anyone noticing. And yet, as I was scooping my jaw off the carpet, it struck me how fluid identity can be, especially in virtual reality. Man, woman, posh, Tory – you can be whatever you want to be. Self-reinvention and social mobility are two of the greatest freedoms of a true democracy. Trouble is, they're also the most fraught with danger. No wonder young people have such a terrible time of it. It almost makes me glad to be 30.