Those whose hunger for closeness overwhelms their concern for their own safety. Those who will, in a poignant bid to hold others' attention, lay out – within minutes of a new encounter – secrets that they would have been wiser to take to the grave.

This isn't to deny the fun that over-sharers can bring to social life. These won't be the types talking about the economic contraction or where they last went on holiday. Contact with other humans should be about getting to the marrow of things they believe, which is why we will quickly get to hear about their ex's sexual difficulty, the vicious row they had about their mother's will, exactly how much they earn, the troubles they have with their digestion, their favourite bedroom position and the nature of an early childhood trauma. The difficulty lies in the toll these divulgences impose on over-sharers themselves. An evening of entertainment is too often followed by a shame-ridden awakening.

Now that the laughter has dissipated, they may feel as though they were seized by an impulse with which they don't identify, an urge to invite others into their deep self without the strength to impose the barest of checks on who they might be.

A painful developmental story tends to lie behind the compulsion. We share too much when we have been too lonely. We fail to understand the risks of overexposure when we have suffered in environments in which so little sincere or real was ever exchanged. We rush to confess because no one showed us a steady, composed route to intimacy. To the isolated former child, no alarm sounds at the thought of having an unbarred conversation with a character who entered the room twenty minutes ago. Such is the promise and lure of togetherness. Such has been the burden of secrecy. We might with time make our peace with remaining somewhat more mysterious. We might more judiciously weigh up the benefits of a sugar-rush of disclosure against the slower satisfactions of safety. We might tell very few people indeed what is going on for us in love, with our health or with work, not because we want to be unkind or boring, but because our first priority has become to look after ourselves.

We don't have to answer too many intrusive questions, nor, as importantly, do we need to ask them. It isn't, we can learn, any reason to panic if we are still talking about what someone did over the weekend or their favourite kind of gloves after the first course.

We don't have to feel boring for ending up, in many, a boring conversation. We aren't dull at heart. We are just calmly working out – in a process that could take months or years – whether we have stumbled on one of those very rare characters who truly deserve to hear from the deepest parts of us.