But it's not all good: when Master20 left home and moved to Brisvegas he also left a big old hole in my heart. I found it especially hard because I genuinely like his company.
But then I can't stress enough how grateful we were to be able to reallocate his room.
Of course, there's always the joy of having them come home for a visit, like Master20 did on the weekend. They fly in and fly out, leaving a trail of dirty dishes and empty wrappers behind them.
Earlier today I was chatting with a mother whose son had just returned from a 24 month gap year (clearly not a maths major) in London and whose daughter lives two hours away in Brisbane. We were discussing how hard it is: filling in the hours we used to spend driving them around and demanding they clean their room.
"I love it!" she said excitedly. "Some nights it's so quiet I go to bed at seven and simply lie there listening to the sound of no-one stomping through the house, no-one ferreting in the fridge and no-one loudly watching crime shows on the telly."
It's nice when the kids can stand on their own two feet and make their way in the world. The flip side is we're not close enough to help when things go wrong. Like today, Master20 was run off the road by a bus. He wasn't hurt, the bus driver waved his apologies and the car sustained no damage, so it's all good. I daresay he needed a hug but, as we're so far away, the poor guy only had his girlfriend to give it to him. I guess I wish we were closer so we could be there when the ugly stuff happens.
"Nonsense," said my friend. "It's better if we don't know what they get up to."
By way of example, she told how the week before she drove down to Fortitude Valley to have dinner with her daughter. They were having dessert when outside on the pavement a disagreement between three blokes suddenly erupted into a punch up.
"How dreadful!" she exclaimed to her daughter.
"Oh, that's nothing," her daughter said. "Last week we sat here and watched two blokes have a knife fight."
"You see?" my friend asked me pointedly. "If she was living at home I'd insist she never went to the that restaurant again and we'd have all sorts of arguments. Instead, she can promise me she'll avoid the place and still do whatever she likes with me none the wiser. I'm happy. She's happy. Ignorance is bliss."
Now Miss17 is weeks away from moving out of home. Fortunately, she'll only be living two minutes away.
When Miss17 first broached the subject we were not at all keen. Her older brother was 19 when he left to go to university. He had savings and sense and a very good reason for going. With Miss17, she just wants to have the experience.
After much thought we decided we wouldn't fight her on this, but we came to an arrangement - if she saved so she had money in the bank before she left we would hold her room for a month when moved out, so she could come back if she found things too expensive or not what she expected or just missed us too darn much. But fyi, we hate the idea of her going. Still, she's nice and close and we'll see her lots and we don't have a lot of knife fights in G-town.
Plus, if things work out, we get to reallocate her room.
When my friend's son surprised this dear lady last week by flying home from London and walking unannounced through her door, she told me she was momentarily thrilled.
Despite not seeing his mum in the flesh for two years he might have spoiled the moment the tinniest little bit when, after giving her a kiss and a long overdue hug, he stood back and exclaimed, "Hey, Mum, you've got old."
She's already suggested he ask his sister if she's got a room free.