Imagination takes us places our minds need to be, but our bodies can't go. All we need is silence and our thoughts. Worlds can be in danger, time can be travelled, creatures can be fought, or befriended, and heroes are made. Where you go is up to you. Unless you haven't gone outside in a few days, then the parents are going to get worried you're not breathing anymore and kick you outside for "fresh air". Pfft, who needs that?