In the end,
it's not the years in your life that count.
It's the life in your years.
                                                                       -Abraham Lincoln

If I had eight hours to chop down a tree,
I'd spend six hours sharpening my ax.
                                                        Abraham Lincoln

Instead of start chopping the tree with a blunt blade for hours and end up a hard work.
It is smarter to first sharpen your blade, clean cut and less work.

Success is not just about doing hard work. It's also about sharpening your skills from time to time. Learning a better way to take down the problems.