Famine and climate refugees lead to authoritarian governments. Or, just have it in the backdrop like a comedy about a heatwave in March where people are sweltering and it turns into a meetcute.
Or just the super fucked up first chapter of Ministry for the Future.
Start saving for retirement now. You can make literally millions by putting away 10% of your income early on. Do it automatically so you never even notice the money gone.
If you are worried about making the wrong choice and your company doesn’t have a 401k, open an IRA somewhere (Fidelity if you need someone to make the decision for you) and pick a date targeted fund. Set up auto deposit. Never look at the balance.
You can always make it better later but for now the best thing to do is start. Don’t let analysis paralysis get in the way.