Photo credits: Man in suit: stokkete, iStockphoto; Climbing tree: wayra, iStockphoto; Racing: Serrnovik, Dreamstime.com; Playing hide-and-seek: diego_cervo, iStockphoto; Watching people: Jarenwicklund, Dreamstime.com; Staring at clouds: gollykim, iStockphoto; Role-playing: Imgorthand, iStock Photo; Dinosaur: JoeLena, iStockphoto; Dog: Bigandt_Photography, iStockphoto; Octopus: Trueog, iStockphoto; Cheetah: Freder, iStockphoto; Falcon: FRANKHILDEBRAND, iStockphoto; Elephant: rhardholt, iStockphoto; Foreign language books: Warchi, iStockphoto; Sports equipment: Michael Flippo, Dreamstime.com; Paint palette: ChrisAt, iStockphoto; Skeleton: selimaksan, iStockphoto; Beakers: agencyby, iStockphoto; Globe: idealistock, iStockphoto; Island hut: ekash, iStockphoto; Writing in journal: ParkerDeen, iStockphoto; Building sand castle: jzabloski, iStockphoto; Boy with crab: IPGGutenbergUKLtd, iStockphoto; Boy in palm tree: Crazy80frog, Dreamstime.com; Running on beach: shalamov, iStockphoto; Horse and buggy: studioworxx, iStockphoto; Scooter: Andras Csontos, Dreamstime.com; Motorcycle: Hirkophoto, iStockphoto; Helicopter: NNehring, iStockphoto; Truck: MCCAIG, iStockphoto; Two-person bicycle: moorlin, iStockphoto; Carousel: Nataliya Hora, Dreamstime.com; Girl on slide: Russ Ensley, Dreamstime.com; Fun house mirror: AshleyWiley, iStockphoto; Hammer game: jganser, iStockphoto; Swing ride: MadCircles, iStockphoto; Fortune teller: Renphoto, iStockphoto; Tea and crumpet: Olga Vasileva, Dreamstime.com; Steak and eggs: wesmyles, iStockphoto; Grapefruits: marekuliasz, iStockphoto; Waffle: uba-foto, iStockphoto; Granola bar: LauriPatterson, iStockphoto; Pancakes: pjohnson1, iStockphoto; Man pushing tire: Ibrakovic, iStockphoto; Woman running: poba, iStockphoto; Man flying: lisegagne, iStockphoto; Clock: Piotr Zajda, Dreamstime.com; Woman in mask: Burocx, iStockphoto; Woman rubbing head: Yuriy Zelenen'kyy, Dreamstime.com