I feel for your "gut". Often, if I'm learning a new math concept, my head says, "Yeah, I can do that manipulation just fine," but my gut says, "Something's not

I feel for your "gut". Often, if I'm learning a new math concept, my head says, "Yeah, I can do that manipulation just fine," but my gut says, "Something's not right here. Nope. Uh huh. Don't like it." And it's very hard to shake gut reactions be they true or false. Here's a rhetorical question: When I read a Kindle-format book from Amazon on the Kindle Cloud Reading app on my laptop, what did I just read? Was it an eBook or not? If not, was it a book in any sense? If someone asks, "Did you read the book, The Cuckoo's Egg?" I'd answer yes, even though I read it electronically -- which is, I presume what the e in eBook stands for. Or do I answer, "No," because it was just digital data on a computer -- absent a standalone eBook device? I have an eBook reader that came as part of the Calibre package, at least they call it an eBook reader -- it's just a program to read epubs. Is it is, or is it ain't an eBook reader?