Why do onions make you cry?!

When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.

When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.

We evolved from onions.
They are our ancestors.
Cutting them up uncovers ancient genetic memories in our brains and we are internally appalled by the horror and grief.

When you cut an onion, there is some type of gas that gets released. When it gets near your eyes, your reaction is to cry.

it's also smell related, if you breathe through your mouth it effects you less/not at all. Obviously dont breathe all over the food though

I`m pretty sure its a strong stench, and it makes your eyes water, which would be a natural reaction.