Successfully doing creative science is hard. The further along you get in a research career the more things are competing for your time and energy and the more distracted you are from your primary goals. This distraction becomes increasingly problematic when it distracts your subconscious as well as your conscious mind. A short post by Paul Graham does an excellent job of describing why this is the case and how you can manage access to that creative part of your brain. In particular he recommends minimizing the amount of time spent chasing money and being involved in disputes. These are both things that we end up doing a lot of in academia and in my experience Graham is right about their ability to consume the productive thought processes we rely on. I also love this quote from Newton:
I see I have made myself a slave to Philosophy, but if I get free of Mr Linus’s business I will resolutely bid adew to it eternally, excepting what I do for my private satisfaction or leave to come out after me. For I see a man must either resolve to put out nothing new or become a slave to defend it.
(via James Horey)
Jabberwocky Ecology 
I think we might be able to go a little deeper (since we are talking about the subconscious). There is a fundamental difference between ‘doing something’ and ‘becoming someone.’ They both influence one another, albeit in different ways. When one focuses on doing things, they may easily lose sight or control of who they become. It is easy to get lost in the tasks we have to do (many of which are important and essential, e.g. obtaining funding, writing a dissertation, collecting data, feeding the kids dinner, etc.) Focusing on becoming someone, however, determines much of what you do. Some of the tasks may be same, but the end result is different. I want to become a creative researcher, therefore I will need to do X,Y, & Z, but can easily ignore A,B, & C. I think that many of us get caught up in ‘doing’ and we forget about ‘becoming’ (particularly common with students).
I agree that managing situations (and distractions) is the best way to keep the right ideas in your head. What you surround yourself with (both mental and physical surroundings) will determine what you do and who you become. As a final thought, I think it is important that the ‘top ideas in our minds’ change often. If my random thoughts never drifted to my three children, I would want to reevaluate my decisions on who I want to become.
Those are both great points. I completely agree that especially when time becomes tight (which is most of the time) that we tend to focus on getting things done when the first step should always be thinking about what it is that we should actually be doing. I also agree that these ‘top ideas’ should change regularly, and in my case at least my brain doesn’t give me a choice. What pops into my head while I’m in the shower bounces all over the place from morning to morning – one morning it’s a great idea for a project I’m working on and the next morning it’s the realization that when my daughter holds the object she’s playing with out in my direction she’s not offering to share it with me, but asking me to tell her what it’s called.