I remember everything about the moment when it came to me that we don't train in order to become enlightened, more we train because it is enlightenment. Of course Zen Master Dogen makes this point over and over again in his writings. It is one thing to read something and quite another to make it ones own, so to speak. When a line of scripture suddenly becomes clear it is all too easy to jump to the conclusion that you now understand what it's meaning is. In one sense you do and in another you're no closer.
When the penny drops, as it did for the chap whose words I published the other day, great confidence can arise and that is good. There can indeed be times when streams of insights follow one another. Yet other times when you wonder if taking up tennis instead might be a good plan! The point is to carry on and not take what comes so personally, i.e. I'm great because I now know, or I'm a looser for even thinking about giving up meditation. Sometimes the wind blows and sometimes the sun shines. Where in this is the concept of progress on the path?
BTW, I didn't realize that 'the penny dropped' was a British term. If you see something here you don't understand please say so.