content warning: confronting the fact that it’s hard to have it all because time only moves one way.
If you want to do something that will take months or years, it’s a good idea to work backwards from the goal to figure out how much time you’ll need to spend and when you’ll need to start. This is one of those obvious things that almost no one does.
For instance, say that you’re single, thirty, and want to have a kid before you’re thirty five. Working backwards you’ve got nine months of pregnancy, maybe six months trying to conceive, and probably a year or two with someone before you’re ready to commit to have a child with them. That leaves about 21 months of hinge dates, partifuls, and pretending to enjoy run club before the math stops working.
I (that’s the royal I, it means me + claude code) made a calculator to visualize this.
This will probably be the least popular image I’ve ever put on my substack. That’s not just because when-to-have-kids discourse is particularly cursed - the very act of backwards chaining from a deadline is anxiety inducing.
Here’s another example: at FLF we search for would-be-founders who want to create new high impact research orgs. Unfortunately we’re on a deadline, because the world is getting crazier with AI, and the window for steering it towards positive trajectories won’t stay open forever.
Working backwards from the goal of having, in two years time, a new twenty person organization decomposes into two phases:
Finding founders: Another process like dating, where exceptional founders who you’d want to support show up at some rate, and each has the probability of being the right fit.
Scaling: Growing the org is an exponential process with constraints, where the doubling time depends on finding good managers, building culture, securing funding, etc. Early orgs might double every six months; more constrained domains might be 12+.
Chain these together and if you want 20 people in 2 years, and your doubling time is 8 months, you need to start with 3 people and hit roughly 3 doublings. That's 24 months of growth - which means you need founders now. Every month spent searching is a month the org isn’t compounding.
Not all goals have hard deadlines, but almost every goal has some kind of implicit timeline. “Lost ten pounds [before I see my ex again]”, “write the next great American novel [while novels are still a thing]”.
The benefits of working backwards are they make your plans and time constraints explicit - this is also why it sucks.
Actually looking at the goal and the implicit plan means seeing the risk and the costs. It brings into conscious awareness the possibility that the plan might fail and that you’re going to have to, probably, make tradeoffs to achieve it. That’s scary, and not looking closely at it lets you stay in sweet sweet ambiguity.1
I also think we're reluctant to commit—and explicit modeling feels like committing—when we don't fully know if we want the destination. Big goals often involve transformation. Becoming a parent turns you into a different person, one who values different things than the person who initially decided to do it.2 Planning for a goal you don’t fully understand yet feels premature, maybe even fraudulent.
Which is real, but alas the calendar doesn’t wait.
One feeling I have when looking at all this: we really need to figure out how to live forever. One lifetime isn’t enough, maybe I’m willing to settle for ten but that’s about it.
On occasion though, past the anxiety and the longing for eternal youth, I can find a certain sense of freedom. It’s liberating to have a goal that you care enough about you want to change your actions to pursue it. There are often a lot of moves you can make, should you really want something to happen. You can:
Devote more resources. Work harder, hire people, do things in parallel.
Relax constraints. Lower your standards, take more risks, push the deadline back.
Be clever. Find hacks and shortcuts, do the ten year plan in six months, find ways to cheat.3
Quit. Change what you want, do something different, make life take the lemons back.
The default cultural scripts we’re given to pursue family, relationships, and careers in this the year 2025 are probably fake, and there’s a lot of room to do better.
If you’re prepping for 2026 - which is the seasonally appropriate thing to be doing - consider working backwards. Make your own calculators and figure out how you might possibly easily have it all… or not.