There is a balance to Stoicism between awareness and anxiety. The Stoics want you to be prepared for an uncertain—and oftentimes dangerous—future, but somehow not worry about it at the same time. They want you to consider all the possibilities...and not be stressed that many of those possibilities will not be good. How exactly is that supposed to work?
The answer lies simply in the idea of presence. As Seneca writes:
“It is likely that some troubles will befall us; but it is not a present fact. How often has the unexpected happened! How often has the expected never come to pass! And even though it is ordained to be, what does it avail to run out to meet your suffering? You will suffer soon enough, when it arrives.”
It may well rain tomorrow, but that doesn’t mean you have to get wet in advance. You can enjoy the sunshine today, while still bringing in your furniture just in case. It’s important not to take the phrase premeditatio malorum (a premeditation of evils) too singularly. When Seneca says that all the terms of the human lot should be before our eyes, and then lists only the bad things, he’s accidentally doing that. Because of course good stuff can happen too. Bad stuff can not happen also.
The point is that the future is out of our control. It is uncertain, and also vast. We have to be aware of that, yes, but we don’t need to suffer, particularly not in advance. Because we have plenty of time to prepare, and plenty of wide open present before us still as well.