It sounds like you might benefit from starting our joining a mastermind. Is that something you have considered?

(I'm not sure how universal "mastermind" is, so here's a link to help explain it a bit, and how to run one: http://www.startupsfortherestofus.com/episodes/episode-167)

Thank you; I had never heard the term mastermind in that context before. Is it a well-known concept? The second result when googling "startup mastermind" is the post you mention, and the first one is... a reddit thread pointing to that same post.

But the idea is exactly what I would need, so thanks!!

Glad to help. I've been in one for about a year or so, and can't recommend it enough.

Not sure how known the concept is, but I think it is fairly well known, especially if you run a bootstrapped startup. And if you're listening to the podcast Startups For the Rest Of Us (recommended!), I'd say it's probably close to 100 percent. One way of finding people for your mastermind is to visit the MicroConf conference, run by the same people as the podcast. (It's a lot easier getting a ticket for the European conference than the US one.)

The mastermind concept is laid out in "Think and Grow Rich" which was published in the 1930s

Same condition here.

I have found that spending time with clients (users in the trenches especially) is enough conversational stimulation I need. I know I'm encouraging the idea of seeing trees instead of the big picture forest ... but as a lone workhorse resource, you want to avoid non-actionable ideas like the plague.