I hardly need to explain what it means but not wanting to grow up and take on increased responsibility is basically the nub of it. When my life suddenly exploded my husband readily admitted to me that he liked spending his disposable income on expensive clothes and going out with his mates and could never envisage a time when he'd happily spend it on nappies, nipple pads and nursery fees instead.
I have to admire him for his sheer honesty and it is down to that honesty that we have decided to move on in life down our own separate paths. So many people have told me how brave we both are to end it now even though we still love each other. We're doing it because of that love, and because neither one of us wants to subject the other to a life of resentment and misery.
I've even had messages from people saying they should have done the same thing as us, because they now have a child with a reluctant father, who brings up the fact he'd rather not be one in arguments - even now. That particular message blew me away in fact and renewed my resolve in knowing that we're definitely doing the right thing.
I've started to feel slight anger, but more at myself than at him. Since it happened a couple of friends have said that although I am only 18 months older than him the gap in maturity was significantly more and it was quite obvious... should I have seen the signs?
Was I blinkered in not realising the fact that I sometimes had to mother him meant he'd never be a particularly good or willing parent himself? Should I have guessed that he might never want me to mother anyone other than him?
It's hard not to beat yourself up in such a difficult situation, but I just have to remind myself how lucky I am to be going through this without recrimination or bitterness. In time we will heal, and stay on friendly terms. And that has got to be something to be happy about.
We spent almost a third of our lives so far together, so it would be a shame to waste it and try and pretend it didn't happen.
I also have to console myself with the fact that having a child with a man-child would not have been a good idea.