Romantically, my university days were extremely patchy. And Valentine's Day – well, it never delivered on my hopes. (I can happily report nobody seems to care about it in London – a fact that only sucks when you have a boyfriend who also doesn't care.)

But every cloud has a silver lining. Those sloppy nights spent in wine-stained single beds with the dulcet tones of someone puking next door, the pining for boys who would ostentatiously leave the bar after formal with that annoyingly not-that-pretty girl who did English at Queens’, and the occasional mad boyfriend too embarrassing to introduce to the parents – all this produced a very valuable angst. It was this angst and a teensy bit of rage (that later diluted to a pragmatic quest for enlightenment) that led to my writing a book about men and their interactions with women, called What the Hell is He Thinking? All the Questions You've Ever Asked About Men Answered.

It's an ambitious title. But it's a useful book to have written and, I hope, to read. I interviewed hundreds of men about their romantic – or non-romantic – behaviour and got them to explain themselves. They analyse mystifying scenarios (for example, why does he act like a boyfriend when you're together but go cold when you're not?) and answer lots of direct questions, from how they feel about tampons to whether they've ever gone off a girl when they see her naked. The men I talked to were mostly 25 and up. But I'm fairly sure I can extrapolate for a Cambridge audience. Here are five scenarios explained with, of course, a little help from our (undergraduate) male friends.

1. He snogs you after formal then passes out in your bed. You had expectations for something a bit more...romantic. Next day, he's awkward and doesn't get in touch after leaving with his shirt skew-whiff and his gown covered in...err...orange juice? Is he just embarassed, secretly keen, or not keen at all?

Rhodri, a third-year, says: “There are figures I've groped while under the influence that, while really very, very hot, would have best been left ungroped. That being said, a bottle of wine does bestow me with the balls to act. There's probably something between you, so next time stop him after the tenth pint and see where it goes.” Bottom line? Alcoholic moves should not be taken as moves.

Daniel Knowles, who graduated this year from Oxford, reminds us of the infinite male potential to be incapacitated by embarrassment. “I've done the very thing you describe,” he says. “I think generally that's a bad way to begin. I always feel extremely awkward following up – even if I wanted to. In which case, some forwardness from the girl might not be a bad idea.” Bottom line: he’s red in the face whether he likes you or not. The only way you’ll find out which it is to drop him a line.

2. You hear through a friend that a guy you've seen around the ADC where you're producing a play (he works in the bar), has asked about you and plans to ask you out to a concert. It's been a week and you've heard nothing. How long before you should write it off?

Rhodri: “When's the concert? There may be organisational benefits to being propositioned a month in advance, but just imagine waiting through the netherzone between the ask and the meet. If he's still not asked you a couple of days before the gig, why don't you ask him?” Bottom line: don’t lose hope as logistics of seeming cool DO concern university men. And once again, pro-activity is to be encouraged (where it will go is a different story). Daniel, however, takes a crueller perspective: “Who knows what he’s got going on. I wouldn’t hold your breath – in fact, I’d say, ignore it completely.”

3. You sort of fancy that grungy historian from the Sidgwick Site who you bump into after 10 o'clock lectures. He seems to fancy you too judging from the increasingly flirtatious banter. But when you finally email him about meeting up, perhaps a touch enthusiastically, he doesn't reply for three days and then only vaguely. Is he busy or not interested?

Rhodri takes the view that he could be genuinely the type that thinks that showering and emailing take too much time. “This fellow's grunge could be due to a lack of showering, and if he's too busy to shower perhaps he's too busy to compose an eloquent (and fully referenced) reply. I've certainly been guilty of both not showering and not replying for this very reason.” Bottom line: undergraduate historian males really CAN be that crap. Daniel, again, takes the crueller perspective: “Not interested. Historians aren't busy – even when working, they're really on Facebook. Your only alternative is very keen to look not interested.” Bottom line: He doesn’t fancy you – and I could have told you this for free – the only way you can change his mind is to appear completely not into him.

4. Should you expect anything from a guy you're snogging on Valentine's Day? If he ignores it entirely, are you allowed to be secretly offended or do all men just loathe V-Day?

Here, ladies, it’s time to abandon any Valentine’s hopes you may have. “For most single guys, Valentine’s Day doesn't even cross the radar. It's a non-event,” says Daniel, with scorn. Or, as Rhodri puts it, “Valentine's Day is a holiday for wet rags, much like Fathers' Day and World AIDS Day. If anything, the pressure to be a superlative romantic would put me off even leaving my room, so don't expect this day above all others to be filled with red roses and Lindt body paint, etc.” Bottom line: just because he doesn’t get in touch on Valentine’s Day doesn’t mean he doesn’t like you. Oh, and boys hate Valentine’s Day.

5. What sounds better to a man at university: loads of sex with lots of girls or a good relationship?

Now here’s a heart-warming one. Basically: a relationship. Rhodri: “I prefer a relationship. Haphazard sex seems like a good idea when you're mashed, but there's no downer quite like waking up the next morning and realising you've got nothing in common, and nothing to talk about. When deadlines pile up and you're feeling hopeless (or you've run out of bacon) it's good to know you've got someone.” As ever, Daniel is Rhodri’s ying (or yang) but thus is malekind: “Fresher year you want lots of sex. Probably second year too. By third year, you've realised that a. you're not getting lots of sex, or any and b. what you are getting is pretty mediocre anyway and c. you have finals coming up, which means stopping drinking, which means definitely no sex unless you're in a relationship.” Bottom line? At the bottom of his heart, he IS “ready for a relationship” so don’t trust him when he says otherwise. Also: the power of beer goggles knows no ends.

Zoe Strimpel’s book What the Hell is He Thinking? All the Questions You’ve Ever Asked About Men Answered (Penguin, £7.99) is out now. See her speak at Jesus on Tuesday 15th February at 9pm. Zoe blogs at zoestrimpel.wordpress.com.