It's more to separate the feeling from the reaction to the feeling by a layer of understanding & examination. Feel first, understand the feeling, examine whether the feeling is appropriate for the situation that caused it, determine how to react, react. It's an OODA loop applied to one's own emotions: Observe the feeling, Orient on the situation, Decide on a response, Act as decided. If you pre-decide to always suppress any reaction you're missing the point. Stoicism is quite similar to modern Cognitive Behavior Therapy. If you just react without thinking you'll often react to your learned habits rather than the actual situation at hand.