This is because no one is perfect - and that's the way we like it. Why would we like that? Because we crave interaction with each other and when we or someone else 'falls down' humans rally together to pick that person up. We want to keep our species strong, so when one of our own is hurting, we naturally want to help.
So yes, we do all fall down, but friends can help pick us back up. Make sure you tell someone when you're falling, in case they're walking up ahead looking at the autumn foliage. They'll hear you and they'll listen.