Chances are, this has happened to you. You walk into a washroom, you really have to go, you open the stall and...
OH MY - there's no way you're going to sit on that toilet. Not a chance. All you want is a clean toilet. Is that too much to ask?
No, it's not. But the fact is, in many parts of the world, people don't even have a toilet - never mind a clean one.
That's the point of World Toilet Day - to raise awareness about the lack of sanitation in developing countries.
The numbers are staggering.
2.5 billion people don't have a clean toilet. Most of those people live in sub-Saharan Africa and Asia.
1.1 billion people have to urinate and defecate out in the open. Most of them live in rural areas, and have to go in fields, bushes, ditches or a plastic bag.
Not only is that unsanitary, it's also humiliating. In Canada, most of us can't stand the thought of an outhouse or a porta potty.
Imagine not having a toilet at all, or not having privacy when you need to do your business? It's pretty much unthinkable.
And yet, in spite of all the advances in technology and modern conveniences, one in three people worldwide don't have a toilet.
As you can imagine, that causes serious health issues including contaminated water and diarrheal diseases.
Those diseases cause thousands of deaths every day, and kill more children in the developing world than HIV/AIDS, malaria and measles combined.
In fact, diarrhea is the second leading cause of death for children under 5 - in large part because they don't have access to toilets.
One child dies every 20 seconds.
Not only that, but a lot of money is being wasted unnecessarily.
The World Bank's Water and Sanitation Program says poor sanitation costs India nearly $54 billion a year.
In East Asia, the cost is about $9.2 billion. In Kenya, it's around $324 million.
That money pays mostly for health care and transporting portable water (for households and farming). Plus, there's the loss in tourism dollars - because western tourists generally want clean toilets.
So, how can we change things? And what's the benefit?
Well, according to the World Health Organization for every dollar that's invested in clean sanitation, there's a return of anywhere from $3 to $34 depending on which part of the world you're in.
Those promises are part of the UN's eight Millennium Development Goals, which include cutting extreme poverty in half by 2015.
The petition will be given to the UN during the 2013 Millennium Development Goals Summit in September of next year.
The Bill and Melinda Gates Foundation are also working on this. Last year, it started the 'Reinvent The Toilet Challenge', calling on engineers to build a better toilet.
The $100,000 first prize went to a solar-powered toilet that turns human waste into energy. It also filters the used water so it can be used for farming.
Incidentally, the $40,000 third prize went to engineers at the University of Toronto.
World Toilet Day and the World Toilet Organization was founded in 2001, by a Singapore businessman named Jack Sim.
And, on a side note, South Korea has opened what it says is "the world's first toilet theme park".
It was built in memory of the former mayor of Suwon, who was reportedly born in his grandmother's toilet.
Apparently, he was obsessed with promoting better public toilets. You can see the BBC's report on the park here.