Without a drainage pipe, the sink can’t actually work. Water would just sit in the basin or overflow, with nowhere to go. It’s a minor detail in terms of size, but it’s essential to the function of the entire fixture. The reason most people don’t catch it right away is because our brains tend to automatically “fill in” familiar components, even when they’re not really there.

This clever brain teaser is a powerful reminder that what’s missing can sometimes matter more than what’s right in front of us. We often focus on surface appearances and overlook the essentials. So next time something seems too perfect or too normal, take a second look you might just notice something important hiding in plain sight.