Ask HN: What are some indicators of being blocked but not distracted?

I've been mulling over the issue of being blocked when working on problems, and identifying the ways we become unblocked.

For me at least, I've found the biggest "unblocker" has been when I have someone to bounce ideas off of. The problem is it either takes me a long time to identify, "oh I'm actually blocked right now", or I know I'm blocked and there's no one available to talk to, OR people are available and I just don't know what words to put together yet, so I'm afraid of starting a conversation as to not waste everyone's time.

And finally, I've found that whomever I'm bouncing ideas off of generally doesn't provide a solution. I end up coming to the solution myself, but having the other person there to keep the gears turning was vital to helping me arrive to my solution.

Now for the actual question: What have you noticed are indicators of being blocked besides the basic things like being distracted or literally being away from your desk. For example, I think looping through the same three files without doing significant analysis on each file is an indicator of being blocked. I'm curious to know any other patterns you've noticed in your own work.