I have found the answer to one of Life's Mysteries today at IKEA. "Why is there urine on the seat in the Ladies Room?"

It is not because some crazy woman is a slob, as previously thought. It is because women take their small male children into the ladies room with them. The culprits are the boys who are not quite old enough to use the men's room alone, but old enough to not be in the same stall as Mom. As long as he is in the ladies' room, he is allowed to use the stall unattended. His hand washing is then supervised, and out they go. It doesn't occur to Mom that Junior might have splashed all over the seat, and it doesn't occur to Junior that anything is amiss. He's damn proud to be using the big commode alone, so what if it doesn't ALL get in. Nobody's perfect!

This does not explain urine on the seat at office situation where no children ever venture, or bars, but at least one can stop wondering about public restrooms.