Hugo explores things that are big, from elephants to trees, to cities and planets. But he learns that big can be all kinds of things, like a big appetite, or a big surprise.
Lily and Felix explain to Hugo all the different ways to be kind, like helping someone who is hurt and taking care of your pets. But when Hugo gives almost all of his balloons away to his friends, he wonders if he's been too kind.
Hugo understands it's good to be fair. But when Hugo gives the same size cupcakes to his huge yeti friend and a tiny ant, the yeti is still hungry. Is that fair?
Hugo can't help but feel jealous when he is left out of a group of friends doing incredible yo-yo tricks. But what is jealousy? Felix and Lily help him find out, and to be happy again.
Hugo learns that heroes are not just ones with superpowers - there are also heroes in real life, like fire-fighters, rock stars, and even his granny. Even Hugo can be a hero to someone.
Hugo learns at school, but also from his parents and friends. He discovers that sometimes you have to make lots of mistakes before you can learn something.
Hugo goes on a journey to discover that tiny flowers and huge elephants are part of nature, and so are forests and oceans and the wind. But are humans also part of nature?
Hugo explores what art is by looking at all sorts of weird and wonderful paintings, sculptures and photos. And he learns that art can make you feel all kind of feelings.
Hugo thinks he's human because he's got legs, ears, eyes, nose and mouth. But his pet spider and his friend the naughty monkey have all those things too! Felix and Lily help Hugo work out what makes humans different.
Hugo's friend the yeti is so sad that he's crying his eyes out. Hugo doesn't know why, but tries to cheer him up by trying lots of things, like taking him to the circus.
Hugo learns that a brain is kind of like a computer, which can store lots of different thoughts that make him feel and remember all kinds of things, good and bad. Lily and Felix help Hugo figure out how memory works.
Hugo knows some things because he can see, hear or touch them. But when he wonders if his friend the elephant can fly, Hugo holds his very own experiment to find out.
What's right? What's wrong? 2+2=4 is right, but is Hugo a little boy or a big boy? Sometimes it's hard to decide on the right answer, and the right thing to do.
Every kid becomes a grown up, even Hugo. One day, he will have to find a job and might have his own house, maybe with his own family! But can grown-ups act like kids sometimes too?
When Hugo is sleeping, he dreams a lot, about flying with dragons and racing with cheetahs. But even when he's awake, he daydreams he can bounce super high in the sky. Hugo wonders what dreams really are, and how do we know they're not real?
Hugo can't wait to grow up so he drive cars, watch scary movies, and do whatever he wants! But he soon learns that grown-ups don't always have the freedom to play like kids do.
Hugo has a great imagination, which helps him conjure up lots of fun and wild games. Felix and Lily show him that he can use his imagination to figure out tough problems and even help people too.
Hugo's friend the yeti loves his teddy and elephant loves his roller-skates. Hugo learns about love by looking at all the things and people around him, and how they make him feel.
Hugo thinks he needs a monkey to play with, badly. But he doesn't think he needs stuff like books or sleep. Felix and Lily help Hugo understand the things Hugo needs and the things he wants.