The answer to this question can be found in the fifth letter of Seneca to Lucilius. In the later part of the letter, Seneca reminds Lucilius of the pointlessness of hope. For the Stoics, hope is the opium of fear. A lot of our disappointment stems from hoping so much in the future and then we start to feel that things will not go in our way we start to panic and fear starts to engulf us that gets worse with time. Hope will lift us higher momentarily only to shake us along the way for the eventual fall.
The Stoics believe that our fate has been pre-determined and so what’s the sense of clouding our thoughts about what the future holds for us. As Seneca beautifully puts it in the letter , “Cease to hope and you will cease to fear.” To make a point further he then writes a metaphor. “Though they do seem at variance, yet they are really united. Just as the same chain fastens the prisoner and the soldier who guards him, so hope and fear, dissimilar as they are, keep step together; fear follows hope.”