You can work hard yet still not benefit from your hard work.
You can be proud of yourself for all your hard work yet not get the benefit you were after.
The three little pigs are a good example. They each worked to build themselves a house.
But building a house out of materials that won't sustain the wind of the Big Bad Wolf, won't protect you from the Big Bad Wolf.
First you have to make sure that what you do will reap the benefits that you are after.
The outcome is not only about how hard you work. It's determined also by if you did the work necessary to reap the benefits that you want.
Knowing what you need to do and how you need to do it is necessary before you waste your time and energy doing things that don't benefit you at all.