EU migration: Romania's absent parents
The children remember exactly how and at what time of day their parents left - Sergiu's mother by plane for Italy at 1pm, Razvan's mother by bus for Italy at 5am.
When I asked the head teacher at the school in Fibis, a village in western Romania, which of his class had parents abroad, he obligingly assembled a little group of them for me, three boys and a girl, all 13-14 years old.
More than 300,000 Romanian children have at least one parent working abroad, according to some surveys. According to official statistics it is 80,000 - although local authorities are well aware that only a small proportion of parents notify them before they leave, partly out of shame. Of these, one in four have both parents overseas.
Last October, the Romanian parliament passed a new law making notification compulsory, but those involved in childcare are doubtful it will be more effective than previous measures. More than two million Romanian adults work abroad, mostly in Spain and Italy. Some stay abroad for years at a time.
Raised by grandparents
Oana Maria's father has worked in the London area for the past six months, in a furniture factory. Sergiu's mum has been away for nine years - he has grown up with his grandparents.
Catalin's mother set out for Germany just two months ago, to look after an old lady near Nuremberg.
Razvan lives with his elder sister now. He was with his mother for a while in Rome, but came home because he missed his friends and extended family.
Of the children I meet in Fibis, Catalin is taking the absence hardest.
His mum Sabina could not come home for Christmas. His aunt cooks for him and his elder brother, but she cannot cook saramale (meat stuffed in cabbage) like his mother does, or the same excellent cakes, he laments.
Sabina was earning 145 euros (£121; $200) a month working nightshifts at a local bakery before she left, her husband Costica explains - about a third of what the family of four needs to live on. He lost his job at the gravel yard four years ago, when it closed down.
Unemployment benefit ended after a year. They now get seven euros a month per child in child support. He does odd jobs around the village, they have hens and a couple of pigs, but the couple decided one of them had to go abroad to work.
In Timisoara, the nearest city, the Save the Children charity runs a day care centre for vulnerable children, most of them with parents abroad, and about half of them of Roma ethnic background.
One girl is 10, and is trying on some white mittens she has just received from Father Christmas when we meet. She lives with her grandparents, as both her parents are abroad. She cannot tell me which country they are in, and breathes a long sigh when I ask when she last saw them. She cannot remember.
"Children growing up without parents is not a new phenomenon in Romania - it happens a lot," says Cristian Badi, a psychologist who runs the children's centre.
"But the real harm is the lack of emotional security in the children - not knowing when their parents might reappear, and for how long."
The centre provides a hot meal a day, as the children often live off junk food at home. Their schoolwork suffers. Some start hanging out in gangs with older kids. Even the money parents send home can be a problem, provoking jealousy among children whose parents still scrape a living in Romania.
Back in Fibis, a low wintry mist hangs over the fields. I listen as Sergiu rings his mother in Perugia. She has lost her job in a chocolate factory, she admits, and is thinking of moving on - but not back to Romania. Probably to Germany, where her sister lives.
I talk to Oana Maria's mother outside the tiny house they live in. They plan to join her husband in England in September, all being well.
Catalin's father Costica says his wife earns 500-600 euros a month in Germany. He will try to persuade his wife to stay, next time she comes home. "Better to be poor but together," he explains.