There’s an inevitable trade-off to be made between the work-life balances of your young adulthood and later adulthood.

Let’s really go back to our school days and start off with a pop quiz. If X + Y = 7, what is the value of X?

Well, that depends on the value of Y. You know that the sum equals 7 so, the higher Y is, the lower X will be, and vice-versa. That’s the thing with algebra – when we’re doing it we’re not just concerned with the individual variables themselves; we’re also interested in the relationships between them. In this case, X and Y have an inverse relationship to each other.

A similar principle applies to the algebra of happiness. Here’s another inverse relationship: let X be your work-life balance in young adulthood, while Y represents the same balance later in your life. Here, too, the more you have of the one, the less you’ll have of the other, and vice-versa.

Why’s that? Well, if you want to achieve professional success and financial security, you’re going to have to outcompete the numerous other young adults also striving for it. Otherwise, they’ll leave you in the dust and you’ll probably never catch up.

But that means devoting more time and energy to your career than to other areas of your life, which will likely suffer as a result. For example, the author’s early success as an investment banker and entrepreneur came at a steep cost, with hair loss, a divorce and a sense that he’d lost his entire twenties.

The point isn’t that you have to sacrifice your young adulthood for the sake of your later years. It’s simply that you must recognize the trade-off to be made between the two – and it’s up to you to decide whether, and how much, you want to trade one for the other.

For example, you can live a relaxed, well-balanced lifestyle in your early adulthood that could make you much happier in the present moment than your career-driven peers’ 80-hour work weeks. But if you choose to take this path, you should do so with the recognition that it could lead to a more precarious financial position later in life. That, in turn, will lead to a more stressful, unbalanced life than the one that those same peers will enjoy in their golden years, as they ease back on work and eventually retire.

That being said, they’ll also have lost out on a lot of happiness between now and then. Again, there’s always a trade-off, but the choice is yours – just know what you’re trading and choosing!