Spontaneous insight comes gradually.
Your mind cannot absorb everything at once, so you have to do it in steps.
One of the key principles in personal development is practice. No matter how you go about becoming a better version of yourself, you have to practice it regularly.
It doesn't necessarily have to be daily (although that's a good thing) but you will need a consistent practice to make it work.
Think of it like a fitness program. If you don't train at least twice a week, you won't make any progress.
Personal development is the same. You commit to it, or don't.
A quantum leap
The reason is simple: you want to increase the probability for spontaneous insight.
In personal development, that's the equivalent of overnight success for the entrepreneur or artist; or enlightenment for the spiritual seeker.
Spontaneous insight is what takes you to a new orbit in your perception. It's a quantum leap of your mind into a dimension, where everything clicks into place.