As a child I wasn't quite fixated on long term solutions and saw things through the lens of each day or expectations of the future. In terms of actions that could have long term impact, it never really did occur to me until my early adult years when I observed the consequences of neglecting ones health for the first time using those around me.
The strange thing was that, in as much as those who developed health complications knew they had to make drastic lifestyle changes, not many took time to reflect on how their lifestyle choices may have contributed to their present health challenges. Am sure for some there was simply no use in doing so, and the only thing that mattered was the illness itself that currently affected them.
A lot of us quite frankly are not long term focused. We might have dreams, desires and expectations, but none of that does anything if the action does not follow. We are also at a time where there are instant dopamine hits everywhere as well as the promise of instant rewards and incentives, however untrue.
Even socially, we seem to be investing time and effort in more accomplishments and more stuff, a mistake if you ask me. Politically, politicians are way too focused on a system that gets them reelected than actions that matter long term. Culturally, we have seen so many changes over the last few decades in terms of beliefs, values, teachings, technology and finance that no one knows how well the next generation will adapt and adjust. That might not be a mistake but it's certainly one that provokes an unclear outcome.
Bottom line is that our actions and decisions do hold genuine long term consequences, and unfortunately a significant number of people sleepwalk thorough it, myself included. So often, we we come to the realization of our mistakes it is often too late and by that time there's no use in regrets.