That may well be some people's experience. It wasn't mine.

Not because I didn't like it: I enjoyed it a lot, I learned things from it, it was one of my favourite books, etc. I still think it's an impressive piece of work. But there was nothing particularly ineffable about it.

So let me try to summarize some of the perfectly effable things that people who like GEB tend to like about it, which might (or might not!) make it worth reading for you.

1. It's a playful book. Hofstadter is having a lot of fun as he writes. (I think this is one of the things that people who don't like the book tend to really dislike: if you don't happen to enjoy the same things Hofstadter does, it can just feel self-indulgent.)

Here's a fairly typical example of the sort of thing he does: the book alternates between ordinary chapters, where Hofstadter might explain some bit of mathematics or talk about an incident in the life of J S Bach or whatever, and dialogues between some imaginary characters. Each of those dialogues is named after a particular piece of music by J S Bach. For instance, one of them is called "Crab Canon", after one of the little pieces in Bach's "Musical Offering" which has the amusing property that it's the same forwards as backwards. So Hofstadter's dialogue is also the same forwards as backwards, and he's constructed it so that the conversation makes a reasonable amount of sense both ways around.

That's a fairly superficial sort of play -- it doesn't have much to do with the deeper underlying ideas Hofstadter is trying to explore, it's just a bit of fun. But he does play around with the deeper ideas too.

2. It brings a bunch of apparently different ideas together and relates them to one another. The "psychedelic" aspects may come from this -- there's something of the "wow, I never realised before, but everything is, like, one thing" to it. And this is another thing that you might either really like -- he's made a bunch of unobvious connections between things you mightn't have seen links between, and connecting things better enriches your mind -- or really dislike, if you feel that the connections he's claiming to make are bogus.

For instance, Hofstadter is very keen on what he calls "strange loops", in which category he includes (1) indirect self-reference, as in the machinery of Goedel's incompleteness theorem or "quining" (copy this down, first without the quotes and then again, after a colon, with them: "copy this down, first without the quotes and then again, after a colon, with them") and (2) what happens when a person thinks about their self and (3) Escher pictures like "Print Gallery" or "Drawing Hands" that somehow show something containing or creating a representation of itself and (4) the way in which DNA codes for proteins which make cells with machinery for converting DNA into proteins which etc. and (5) rather more tendentiously, one of Bach's canons which ends a tone higher than it starts so that if you kept on playing it the key would keep rising and rising. The common theme is something about traversing levels of a hierarchy and somehow coming back to where you started. If you agree with Hofstadter that this is an interesting and important general phenomenon (he thinks it's essential to how conscious minds work) and that all these diverse things are cases of it, then you'll find this enlightening, maybe even exciting. If you think he's just grouped together a bunch of things with little in common and convinced himself they're all the same thing, then not.

3. It talks about some really quite exciting mathematics (at least, for those who are able to be excited by mathematics): Goedel's incompleteness theorems. If you just want to learn about how Goedel's stuff works, you can get that more efficiently and probably more clearly in other places. But Hofstadter's explanation isn't so bad, and he intertwines it with all those other things he's interested in, and once again you might like it or hate it. In any case, for many people GEB was their first exposure to the idea that some statements that are just about the properties of the positive integers might be provably neither provable nor disprovable, and to the neat techniques Goedel cooked up by which, in some sense, statements about properties of positive integers can "really" be "talking about" mathematical statements and proofs and whatnot, and these are (again, for some subset of the population) exciting ideas.

4. Escher made some really cool pictures. Bach made some really cool music. If you happen not to be familiar with them before reading GEB, then being introduced to this cool stuff is a pretty valuable service GEB can do you.

5. Chunks of GEB are about artificial intelligence. The world of AI has changed a lot since GEB, of course, and today's AI systems don't have at all the sort of structure I think Hofstadter expected them to have. (It may be that they have some of that structure "hidden inside" -- artificial neural networks are mysterious and inscrutable in something like the same way as brains are -- but I think Hofstadter was expecting that structure to be in the code.) I haven't read GEB in a while and won't try to pronounce on how much value his thoughts-from-way-back-then have today. But I think one thing some people have found exciting about GEB, especially when reading it early in life, is that it was the first thing they read that took seriously the possibility that computers might be able to think in something like the same way as humans, and tried to think about how that might work. The ideas of AI are much more "in the water supply" these days; I doubt anyone will first hear about them from reading GEB any more.

6. (Same theme as 3, 4, 5.) There are just lots of interesting things in GEB. Zen koans. Fractals. Winograd's "SHRDLU" AI system. Bacteriophages. Non-euclidean geometry. Srinivasa Ramanujan. Etc. You won't learn much about any of these things from GEB, but encountering them at all is delightful if one happens not to have seen them before. So the experience of reading the book, if one happens not already to know everything, is one where at any moment you may suddenly encounter some fascinating new thing.

I am not claiming that you should read GEB. It's pretty long. All the individual things you could learn from it, you could learn another way. If you're a generally-well-informed adult, you probably already know a lot of the things some people first encounter in GEB. You might not share Hofstadter's taste in wordplay and the like. But it definitely has merits that can be described.