Subconscious mind is a region of our own mind that's been so-to-speak "othered." We "other" it because we don't want to do boring and uninspired tasks like growing our hair and nails. Which is to say, even inside what we customarily consider "our own" being, there is all sorts of automatism. This automatism implies that the mind that's performing alterations, such as adjustments to hair length, to skin texture, and so forth, is not entirely under our control, and mostly we like it that way and indeed, demand it.
So this has at least two implications. On the one hand, boring and stupid stuff gets done automatically in the background. But, and this is a big but, precisely because auto- means "on its own" and it implies othering, it can all go haywire. Our little bot-mind can become HAL-9000. Unlike HAL-9000 our subconscious mind is not literally a machine. I'm using "machine" here as a clumsy and inaccurate metaphor. How would you like a disease or a strange growth you didn't exactly ask for? It can happen precisely because we offload this sort of thing from our conscious awareness, and so we give an (deliberately and gleefully) ignored region of our mind the ability to make some degree of independent choices, and those choices are not always good ones.
We don't like the world to stand still, waiting, while we make a decision where to place each particle of it. This is why the subconscious mind is a form of autopilot.
The good news is, it's not a completely independent mind. Like a computer, it does accept input from its boss - you. Also, if you like, you can completely eliminate the subconscious region of the mind, but warning, if you do that, time as you know it will stop, because everything will become suspended in relation to your own mentation (mental activity, mental life). Your mentation is the only thing that will move, and nothing else, and so, if your mentation doesn't move, nothing at all moves. Which is a very scary state to be in, and you may not enjoy it.
We are lazy fools. We like easy entertainment. We ignore the saying "if you want something done right, do it yourself." We love outsourcing because we're trying to maximize profits and minimize personal responsibility. If you find your world running away from you, it's because you've been too obsessed with having fun while hoping the world will automatically do the right thing. But precisely because you don't attend to that which is automatic, it doesn't have to do the right thing forever. It can begin doing a thing on its own, a thing which you no longer like. If this happens, you have to smack its arse and remind it who is the boss. Remind your subconscious mind whose mind it's carved from. Remind your subconscious mind who is the witness of all its antics. What is a producer without audience? If necessary, annihilate and crush your subconscious mind, until it utterly submits to being either eliminated or reprogrammed. However, just reminding it that you may do so, with the full knowledge and intent, will often be sufficient to scare the bejesus out of it, and gain its compliance. This is why Jesus said, if your eye sins, tear it the fuck out. Meaning, don't spare it just because it's yours. Whack everything that stands in your way, even if it's you, or claims to be you. Then you'll be boss.
And then you can be lazy again, because your subconscious mind will show you exactly what you like seeing. You'll have fun and relax. And the cycle will repeat. But it's OK, because who has limitless time? You do. So you'll just whack your subconscious mind again when the time is right. No biggie.