The Kokiri's fairy has to keep the magic projecting into the glider or else it doesn't go to fast... and it's the Kokiri's job to turn and keep it out of the shade! Link kept one until he came into Hyrule, which is when he found out he couldn't use it there. Reason being mostly because now that he had a connection with his own world (because he's a Hylian, not a Kokiri) he started feeling more... "Hylianish". And though Link still once in a while used it because Navi never left him, there was also the disadvantage of night-time in Hyrule. Link, being a Hylian who has barely set foot on his own land, soon discovered the disadvantages of a world that turns from day to night, night to day every twelve hours or so.

It surprised Link very much when it turned dark at night because in Kokiri Forest, the magic keeps it from turning from day to night... hence it's always day there. At night time he kept wondering why he was so upset about a "blanket over the sun" and why everyone else were climing into there beds! Though Link slept to, Kokiri mainly slept when they wanted to.