A baby hippopotamus lies next to its mother on the first day it was presented to the public at the Zoo Berlin zoo on November 1, 2011 in Berlin, Germany. The baby hippo was born at the zoo on October 23. (Photo by Sean Gallup/Getty Images)

Last weekend, the National Building Museum in Washington, D.C., opened a 10,000 square-foot ball pit to the general public, and everyone cheered that, finally, someone made their childhood dreams come true.

A girl sticks out her tongue during snowfalls on a street in Hefei, Anhui province February 13, 2014. (Photo by Reuters/Stringer)

Father Christmas hands out presents to children at the Aid And Adoption Society home at Leytonstone. (Photo by Gerry Cranham/Fox Photos/Getty Images). 7th December 1938

Festival goers wear Australia day attire at Big Day Out 2012 at the Sydney Showground on January 26, 2012 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Ex On The Beach star Charlotte Dawson out on the town with friends on the party island Ibiza, Spain on October 3, 2016. (Photo by Jon Baxter/ICelebTV)

A rickshaw driver looks out the windshield as he drives onto the highway in Mardan, Pakistan January 30, 2017. (Photo by Fayaz Aziz/Reuters)