Don't you feel like you would have improved at this regardless of whether your schooling put a concerted effort into it? I've forgotten a lot of things from sch

Don't you feel like you would have improved at this regardless of whether your schooling put a concerted effort into it? I've forgotten a lot of things from school -- doing math in my head isn't one of them because I use it all the time. Is that evidence that it's a good investment of time for 1st graders, or is it evidence that you would have learned it anyway due to the utility of it?