My husband and I recently had a very serious talk about communication issues. Apparently he'd been under the impression that every time I was enthusiastic about something, I was seriously planning to drop everything and do it. This led to a model of me as a horribly impulsive person he had to hold back from disaster all the time, whereas I saw him as constantly shooting down everything I wanted to talk about. For no reason!
Last night, he explained that he doesn't have strong, positive emotions about things until he's already decided they're realistic and probable. I, on the other hand, have strong enthusiastic emotions about things without any sense of commitment at all. Basically: I prefer everything remain on the table as an option until I might actually want to do it, at which point it will be evaluated for risk and viability. He prefers that things not even go on the table unless they've been evaluated for risk and viability.
At first, when we were trying to figure out how to fix this in conversations, he asked "Can you just tell me when you are or aren't being serious, and then I'll know how to respond?"
I replied, "That sounds exhausting, having to decide right then if I'm serious about the thing every time. Like, having to decide if a small desire or interest is worth the effort, I'll usually decide it's not. But then little ones will build up, and it's not like I can batch them all in one conversation, since they're all different." It's obvious to me how this can turn into festering resentment over time; no matter how many little ideas and "maybes" accrue, the effort of resolving them the way he's inclined to would always be larger.
The work of evaluating how serious I am, or how risky something is, doesn't belong that early in my cognition. I do the work, but not until much later in the decision making process. I use conversation and hypotheticals (and what apparently looks like enthusiastic, committed planning) as exploratory world-building. Unknowingly scaring the shit out of my husband.
The exploratory world-building itself is an exhausting time investment for him, so why would someone engage in it without being serious? He thought every time I was excited about a new career idea, I was actually going to drop my current job and pursue it, or every time I saw a cool house on the market that I was playing with the idea of, I was actually going to try to move there. I thought he was just being a wet blanket, ruining my fun by bringing up worst case scenarios for everything I wanted to talk about. It took about...ten hours of conversation, all told, to find the crux of the issue.
I might generalize this to: different cognitive processes take different amounts of work for different people. Deciding how serious someone is about something based on how hard their actions are for you can lead to a lot of confusing resentment and fear, not to mention bad predictions about their behavior.