But this impression of children is not typical. One year on from the start of NATO's bombing campaign, most schools are now heated, weatherproof and open, though they are still in need of improvements, according to Steffie Schnoor, joint head of the department of education and science in the United Nations' interim administration in Kosovo.
At Eleni Gjika primary school in Pristina, for instance, the windows have been repaired, the children have textbooks, the head's office is piled with new equipment and the school is beautifully repainted on the outside - a project funded by an American charity.
Inside, however, plaster is falling off walls, children are crammed on to battered benches, and everywhere is scruffy and covered in graffiti. In a newly refurnished room, the radiators are lying on the floor.
The UN administration's working parties - dominated by Kosovars - are already at work on a new curriculum.
Steffie Schnoor has strong ideas about it. It must, she said, be unified for all communities in Kosovo. It needs to be more balaned, with less community language, and more science and maths. She wants to see methodological changes, too: more child-centred learning and more interactivity.
Obvious blots on this picture are the tent schools. Some are there because schools have been damaged beyond repair. Others, though, represent a much deeper problem.
Before the war, children from different communities shared school buildings, using separate classrooms, but, Ms Schnoor said, children are no longer doing that because they are afraid. "Romany children are afraid to go to a Serb school, and Serbs and Albanians don't go together," she said. So, tents are needed to provide separate schools.
Kosovo's minorities are presenting the UN with other problems, too. While suitable Bosnian, Croatian and Turkish textbooks have been found, and are being distributed, Serb books are still "at the review stage".
There is real enthusiasm for education in Kosovo, however. The Eleni Gjika school buzzes with energy. An after-school poetry reading is packed.
Steffie Schnoor has one overall aim: to get rid of hatred. "The only possibility is to do it through the children," she said. "They can influence their parents. But it's not a short-term project."