Does anyone actually know what causes those painful under the skin pimples or is skincare just guessing?

Real question because I genuinely cannot crack the pattern.

Some months my skin is completely fine and then suddenly I get one of those painful deep pimples that feels like it has roots and a mortgage under my skin.

People say hormones. Stress. Dairy. Sleep. Dirty pillowcases. Looking at the moon incorrectly. I’m kidding. Sort of.

Have you actually figured out what triggers yours? Or does one just appear randomly to ruin your confidence for a week?