Whoa, dude. Your abstract stuff is awesome! Why haven't you posted that in the art forum before?
As for your question, of course people's interest in subject matter changes! Kandinsky, one of the first to paint pure abstraction (and one of my all-time favorite artists) learned to paint realistically and gradually became more interested in shapes and colors rather than depicting reality. It's good to explore new ways of drawing. Now that you've thought about it, it might be good to ask yourself if you're satisfied just spacing out and drawing (which is fine), or if you want to develop this style further.
Also, if you want to keep drawing representational (basically it means the opposite of abstract), it's not like you can't got between styles. You might need to practice extra hard to get back into the groove of it, but the knowledge is still in your brain.
^_^