Even before the Covid pandemic forced us all to stay at home and stop travelling, people talked about an "epidemic of loneliness", where millions of people felt isolated and didn't get enough company to enjoy their lives.
We all know the feeling. There must have been times when you'd like to have a friend to play with or talk to but there's no one around. But for some people, every day can be like that. A study in France a few weeks ago found that one in three old people felt that way. And even lots of young adults feel lonely.
More and more families live a long way from their grandparents, cousins and other relatives. People who are ill are often stuck at home.
People are coming up with solutions though. Last month, the city of Krakow, in Poland, was the latest to join a global trend of setting up benches in parks and on the streets where strangers can meet, sit down and talk. It all started two years ago in Cardiff, Wales, when a lady called Alison saw an old man sitting alone and she wasn't sure if she would disturb him if she spoke. So now benches around the world have signs on them reading "Happy To Chat".
Another solution is getting to get to know your neighbours better. WoW! News went to meet people who got together to build their entire apartment building. They made sure there were lots of places, including a big garden, a laundry room and a big space for parties, where everyone in the building is welcome and can meet up. For kids, there are always lots of friends - and older people who can look after you if your granny doesn't live near you.
Éloïze, who's 14, told us: "In a normal building, you might get on OK with the neighbours but you don't really do much with them. Here, it's a bit like being one big family, or having lots of friends. It's like we live together - but separately!"
To see how it works for Éloïze, Théophane and their neighbours in Strasbourg, in France, head on over for the latest on the WoW! News app.