What are the techniques to get over the learning plateau? I often end up having loads of things which I am learning. One of the pattern which I have observed over time is that I often end up leaving things half way - for months and then, I have to restart doing the basics again. I feel that if only I ended up taking a few steps more, I could have gained much more from my revisions.

I have a couple of questions - 


Is this good practice?
Is there any cognitive reason behind this?
How does one overcome/control this tendency to start off something new before finishing the older ones?
Increased spacing between learning sessions has been found to improve long-term learning when studying for tests. The key is to study less per session, but more often. To develop a habit, you could start by connecting your time of study to a habit that you have already established. For example, if you always brush your teeth, you could associate putting the toot-brush back with walking over to your study area and opening a book.

Repeated learning further enables learning. This is one of the reasons spaced learning works. Once you have studied a chapter the previous session, you go back to the same chapter, skim it, and think about the concepts that you have learned. Repetition is key to rote learning.

Facing the hard parts requires a very thorough understanding of the basics. Know the basics. Don't be afraid of your brain working harder on some problems. The more advanced stuff will take more time to learn. That is the natural course.

TLDR:


No.
A lack of repetition, spacing, and knowledge of the fundamentals.
See above.