That’s not a universal “major mistake”—it really depends on context.
In many places, especially where water is scarce, people follow the rule “if it’s yellow, let it mellow; if it’s brown, flush it down.” This reduces water usage, since toilets can use several liters per flush. From an environmental standpoint, not flushing every time can make sense.
But there are trade-offs:
- Hygiene & odor: Leaving urine sitting can cause smells and bacterial buildup, especially in warm climates.
- Shared spaces: In households with multiple people or guests, not flushing is often considered inconsiderate.
- Plumbing & cleanliness: Over time, it can lead to staining or mineral buildup.
So it’s not inherently wrong or right—it’s a balance between water conservation and cleanliness. A practical approach is to adjust based on your situation: conserve water when appropriate, but flush regularly enough to keep things sanitary and pleasant.