Stoicism is a philosophy founded by Zeno of Citium in Athens in the early third century BC that revolves around implementing calm, resilience, and emotional stability, which also means to remain calm during under-pressure and not letting emotions take over. The point of stoicism is basically to stay calm and collected. It's when we're being faced with life events, especially the negative ones. Instead of believing more positive outcomes from our worries and fears, stoicism forces us to think about the negative possibility and our capability to make it maneuverable to see that we are more than capable of enduring those things. The Stoics believe that stoicism is more than attitude, as there's a cause and effect. People are forced to think about all the negative outcomes that might happen later, but instead of overthinking and making ourselves worry about that more, we're given a perspective that these things aren't the end of everything. May we don't have control over things that happened or are about to happen to us, we can control our approach to deal with them.
Stoicism teaches us about embracing plans with both positive and negative outcomes based on our perspectives. If the negative ones are unendurable, then there's no other way - just continue facing it (for example, grieving). The next question would be - how do we endure it? How do we get through it? The Stoics believe that death is a natural process, and accepting the fact that eventually, it will happen, and learning how to accept what happened, and changing the thought wishing that it has not happened. This phenomenon is called the "art of acquiescence" - is to take on rather than fight it.
Simply put, stoicism aims to minimize negative reactions coming from our end, which is within our control to reach happiness. Stoicism can be applied to spread positivity and peace. In life, accomplishments and failures are parts of life that we can't avoid, while sometimes, we see the latter as a negative outcome. The advantage of this philosophy is proven by Bill Gates, who used stoicism as part of his daily life.
The Stoics believe in practicing negative visualization - contemplating what could go wrong, the worst case possible, and what would happen beyond our control. To face these unpleasant feelings is to prepare ourselves for the worst possibilities that might appear. Doing this will help the stoics to eliminate the element of unexpected things happening. They do this with their eyes wide open, which is acknowledging the hurdles and difficulties they're about to face and being prepared for them. By being stoic, there will be no failures, according to their perspectives, only outcomes.