Have you ever tried to boil water? If you have, or have seen someone doing it, you may have noticed that it takes some time. Now, imaging that you turn the fire off before the water is boiled and turn it on later, turn it off again before it is boiled and turn it on later and so on. When are you going to get the water boiled? Aren’t such operations a waste of time?
The same applies to any objective you have. If you want to be effective, you need put continuous effort and not stop until reaching your goal. If you want to learn something, you should study and learn until you understand it, and not abandon in the middle. Having started and not finishing is just like not having started at all. Pretty much useless and a great waste of time.
If you lived on the tenth floor, there were only staircases and you decided to go home, you should continue walking until reaching the tenth floor. If you abandon and get to sleep at the seventh floor, it is not much different from not having tried to get home at the first place. If you are going to take a journey, make certain you will not abandon half way. It should be like taking a flight; once you get on, you will get to your destination.