Looking at your experience, all we have is "now". But I wonder, what is "now"? Let's look at language and thought. Whenever one thinks of a word, e.g. "cat" and has it in their mind, I have the perception that I have this word totally grasped in my mind. However, it takes a time which is not equal to zero seconds for this word to pass through my mind. If everything is now, how does perception exist? Without time, how can sensations and perceptions exist and change?  I'm just thinking, that it's all truly spontaneous. It comes from nothing. In my present moment experience causality doesn't exist. There is this experience and I don't know why it is. And if we say that time does exist, then things still change spontaneously. Because no matter how small a chunk of time you consider, it's a mystery why anything happens at all. Reminds me a of calculus a bit here.  As for why I used the word discontinuous, imagine a graph with a line. A line has an infinite number of points in it by definition, and its continuous. But a point has no size, and there is no lee way to move around and have change. I used the word discontinuous because of its connotations in studying maths.