When a plan dies, the skills you built for it don’t. They transfer to whatever you build next.

Losing the plan and losing the preparation are two different losses, and only one of them actually happened. The hours you put in changed what you can do, and that change is stored in you rather than in the plan. What you learned about focus, about finishing, about working when it was dull, all of that stays.

Before deciding the time was wasted, make a plain list of what you can do now that you could not before you started. Keep it concrete: software, a language, a way of talking to strangers, a tolerance for boredom. Then look for where those things apply next.