Sorry, we're about to ruin your childhood. That is unless you're the one person who actually read the rules to Uno.
For most, the Wild Draw 4 was that one card you would hold on to and play it as soon as someone got down to one card. Or you'd all gang up on one person and play several in a row, making them draw 4 multiple times in a row. It's evil, but so much fun!
Unfortunately, we've been playing that card allllllllll wrong! The real rule is you can only play that card if you don't have any other options. And if you get caught lying, then you're stuck drawing cards.