What's the mental burden of trying to do something? What's it cost? What price are you going to pay if you try to do something out in the world?
I think that by figuring out what the usual costs to doing things are, we can reduce the costs and otherwise structure our lives so that it's easier to reach our goals.
When I sat down to identify cognitive costs, I found seven. There might be more. Let's get started -
Activation Energy - As covered in more detail in this post, starting an activity seems to take a larger of willpower and other resources than keeping going with it. Required activation energy can be adjusted over time - making something into a routine lowers the activation energy to do it. Things like having poorly defined next steps increases activation energy required to get started. This is a major hurdle for a lot of people in a lot of disciplines - just getting started.
Opportunity cost - We're all familiar with general opportunity cost. When you're doing one thing, you're not doing something else. You have limited time. But there also seems to be a cognitive cost to this - a natural second guessing of choices by taking one path and not another. This is the sort of thing covered by Barry Schwartz in his Paradox of Choice work (there's some faulty thought/omissions in PoC, but it's overall valuable). It's also why basically every significant military work ever has said you don't want to put the enemy in a position where their only way out is through you - Sun Tzu argued always leaving a way for the enemy to escape, which splits their focus and options. Hernan Cortes famously burned the boats behind him. When you're doing something, your mind is subtly aware and bothered by the other things you're not doing. This is a significant cost.
Inertia - Eliezer Yudkowskoy wrote that humans are "Adaptation-Executers, not Fitness-Maximizers." He was speaking in terms of large scale evolution, but this is also true of our day to day affairs. Whatever personal adaptations and routines we've gotten into, we tend to perpetuate. Usually people do not break these routines unless a drastic event happens. Very few people self-scrutinize and do drastic things without an external event happening.
The difference between activation energy and inertia is that you can want to do something, but be having a hard time getting started - that's activation energy. Whereas inertia suggests you'll keep doing what you've been doing, and largely turn your mind off. Breaking out of inertia takes serious energy and tends to make people uncomfortable. They usually only do it if something else makes them more uncomfortable (or, very rarely, when they get incredibly inspired).
Ego/willpower depletion - The Wikipedia article on ego depletion is pretty good. Basically, a lot of recent research shows that by doing something that takes significant willpower your "battery" of willpower gets drained some, and it becomes harder to do other high-will-required tasks. From Wikipedia: " In an illustrative experiment on ego depletion, participants who controlled themselves by trying not to laugh while watching a comedian did worse on a later task that required self-control compared to participants who did not have to control their laughter while watching the video." I'd strongly recommend you do some reading on this topic if you haven't - Roy Baumeister has written some excellent papers on it. The pattern holds pretty firm - when someone resists, say, eating a snack they want, it makes it harder for them to focus and persist doing rote work later.
Neurosis/fear/etc - Almost all humans are naturally more risk averse than gain-inclined. This seems to have been selected for evolutionarily. We also tend to become afraid far in excess of what we should for certain kinds of activities - especially ones that risk social embarrassment.
I never realized how strong these forces were until I tried to break free of them - whenever I got a strong negative reaction from someone to my writing, it made it considerably harder to write pieces that I thought would be popular later. Basic things like writing titles that would make a post spread, or polishing the first paragraph and last sentence - it's like my mind was weighing on the "con" side of pro/con that it would generate criticism, and it was... frightening's not quite the right word, but something like that.
Some tasks can be legitimately said to be "neurosis-inducing" - that means, you start getting more neurotic when you ponder and start doing them. Things that are almost guaranteed to generate criticism or risk rejection frequently do this. Anything that risks compromising a person's self image can be neurosis inducing too.
Altering of hormonal balance - A far too frequently ignored cost. A lot of activities will change your hormonal balance for the better or worse. Entering into conflict-like situations can and does increase adrenalin and cortisol and other stress hormones. Then you face adrenalin withdrawal and crash later. Of course, we basically are biochemistry, so significant changing of hormonal balance affects a lot of our body - immune system, respiration, digestion, etc. A lot of people are aware of this kind of peripherally, but there hasn't been much discussion about the hormonal-altering costs of a lot of activities.
Maintenance costs from the idea re-emerging in your thoughts - Another under-appreciated cognitive cost is maintenance costs in your thoughts from an idea recurring, especially when the full cycle isn't complete. In Getting Things Done, David Allen talks about how "open loops" are "anything that's not where it's supposed to be." These re-emerge in our thoughts periodically, often at inopportune times, consuming thought and energy. That's fine if the topic is exceedingly pleasant, but if it's not, it can wear you out. Completing an activity seems to reduce the maintenance cost (though not completely). An example would be not having filled your taxes out yet - it emerges in your thoughts at random times, derailing other thought. And it's usually not pleasant.
Taking on any project, initiative, business, or change can generate these maintenance costs from thoughts re-emerging.
I identified these seven as the mental/cognitive costs to trying to do something -
*Altering of hormonal balance
*Maintenance costs from the idea re-emerging in your thoughts
I think we can reduce some of these costs by planning our tasks, work lives, social lives, and environment intelligently. Others of them it's good to just be aware of so we know when we start to drag or are having a hard time.
Thoughts on other costs, or ways to reduce these are very welcome.