That's not quite right! Sugar actually dissolves in cold milk just fine. It might take a little longer than in warm milk, but it will still dissolve completely.

Here's why:

* Solubility: Sugar is soluble in water, and milk is mostly water.

* Temperature: While warmer temperatures generally speed up the dissolving process, sugar is still soluble in cold liquids.

The reason you might think it doesn't dissolve is that:

* Dissolving takes time: Sugar dissolves more quickly in warmer liquids, so you might notice it dissolving faster in warm milk.

* Stirring helps: You can help the sugar dissolve faster in cold milk by stirring it well.

* Sugar crystals: Sugar crystals can be small, and sometimes they just appear to be sitting at the bottom of the milk if it's not fully dissolved.

So, don't worry about your sugar not dissolving in cold milk. Just give it a little time and stir it up, and it will disappear into the milky goodness!