- i could parse the statements that the speaker was saying and writing on the blackboard, and they seemed reasonable,
- i had no idea what was going on.
yes, this should be a normal, even average experience for mathematicians. we are ultimately specialists, after all, and aside from our (few) topics of interest and expertise, there is little that we truly understand.
i suppose it means that, at my current university, we've been inviting speakers whose work is very common to ours. as a result i haven't really had to deal with utter confusion on a regular basis.conversely, i get a little nervous when the proof to a theorem is a little too simple. it either means that there is an error somewhere and i missed the difficult, worthwhile part, or that the theorem wasn't "worth" proving.
confusion, however, is oddly comforting .
it suggests that maybe we are approaching the boundaries of our understanding; perhaps doing so, we can extend them.
in other news, this research visit has gone very well so far. my co-author and i are making a lot of progress .. and of all things, our ideas from last time actually seem to be working! (-:
i liken it to going hiking with the right trail companion: every day there's ground to cover, so when one is going at a good, hard clip, one can't help but feel good .. from the shared experience of an honest day's toil.
 unless, of course, the speaker or author is doing an incredibly bad job at exposition, in which case it's just unnecessarily frustrating.