We can't control our emotions, but we can control their expression. Unless there was an organic or psychological reason for it's inhibition. Sociopathy, as an example. Controlling emotions truly has nothing to do with education or culture. This are just universal physical indicator. You could be the most educated person on the planet, and unless you’re a sociopath, you will still express it in what are called "microbursts or leakage." That flash of facial expression that occurs before you can suppress the full expression.

You can use your mind to calm yourself and be more self aware, through breathing exercises, etc, but you want to learn from your emotions, not control them, as they're a guidance system for how to operate in the world and with others. You may in fact be able to train yourself to suppress the expression, or modify the triggers in some way, but you cannot eliminate the indicators. Emotions are basically a visceral reaction to surrounding stimuli. We still experience the startle response, pulse gets elevated, adrenaline starts getting pumped into your system, you feel twitchy, that is triggered by any number of stimuli and is connected to the "fight or flight" physiological state. Which in turn can give rise to any number of actions.

In some moments—more as you mature—have more self control, because you're brain keeps processing it or just cancels out the process altogether. Like if you held a very hot plate, you might drop it, but if it someone's very special plate then you'd override the process and hold onto it. Like you think you're on the train waving to someone in the boarding area, only your not on the train and there it goooeess. This is just an example and isn’t related to emotions but you get my point.