When you are young if your interests are in areas that are also high paying(software, medicine etc), then it's gold.
Assuming you have a high saving's rate, if your interests change, then you have the flexibility to switch to almost any other interest with the backing of the built-up FU money.
Same can be extended to geography as well. When you are young, if your place of interest happens to have a high cost of living, then later if your interests change, you can easily relocate to a cheaper place. But if your place of interest is a cheaper place when young, then moving to a higher cost of living place when you get old is not easy.