If you are older, and are taking blood thinners, if you have a disease or condition that keeps your blood from clotting properly, or if you are soon having surgery, you may find yourself with some unexpected dietary restrictions. Onions and garlic, especially raw onions and garlic, are off the plate.
There's an evolutionary reason why people cry when they cut onions - it's the body's way of keeping us away from dangerous chemicals. And it's such a useful adaptation that every living animal on Earth possesses it.
There's a saying that a watched pot never boils. You could also say that a watched plant never grows—unless it's being watched by a laser-wielding, 3D plastic sculpture-printing, growth-tracking megarobot.