To thoroughly complete a task is to leave no parts undone, to do it to the best of your ability, until it reaches your own definition of perfection.
Unfortunately we take on so many tasks that being thorough in all of them is nearly an impossible feat to accomplish. From teamwork, to class work, to actual work and everything in between it has become natural to overload our plates quite figuratively and also quite literally (I mean we sometimes put so much food on our dinner plates that we can't fully enjoy each and every dish).
But why would you keep doing something if you weren't doing your best for it?
This isn't saying we should stop doing the things we once enjoyed, but now are maybe too busy to fully love doing anymore. It is just simply saying we must evaluate our thoroughness in each task we take on.
With love for each and every task in our lives comes thoroughness.
So take each one on, love every bit of them and most importantly learn to be thorough in all of it.