So I wrote a post response to a question on AT, and I liked what came to mind enough to want to expand on the idea here so....
And I suppose I do, though for various reasons I don't really think of myself as a Collector the way some people are: I keep all my decks in simple bags in a large sack (after fire last fall, I like the idea of being able to quickly grab and take them all in an emergency), and care about boxes not at all - the only reason I keep those these days is for possible trading purposes, as other people seem to like keeping their decks in proper boxes with proper LWBs. I don't care about keeping my decks in 'mint' condition, even some of the rarer, OOP ones - if I think it will look better trimmed, I trim away, and gilt them too. I do not keep decks I cannot or do not want to read with, no matter how pretty or rare - all of my decks must be reading decks, working decks, because what the hell do I have them for, if not to read with?
See, we all call it 'tarot reading' but in many ways that seems to be mostly a metaphor, figurative language. Do we really think of it as the equivalent of reading a newspaper, a book? And yet, the more I think about it, the more I want to say...perhaps yes. What is written language, after all? From the earliest pictographs to modern, current alphabets in a way, if you think about it broadly, writing is about visually representing abstract concepts. We have these little symbols we call letters, and we string them together this way and that, and suddenly that MEANS something to us, because we have been trained to automatically interpret them as such. So when you come across DOG, you do not see random squiggles: your mind automatically brings up the image or the idea of a certain canine animal. And when you learn other languages, you apply the same concepts. PIES brings to mind the same animal for me, because my mind has been trained to make that associated. So does كلب because again, written language acquisition is about training the mind to correlate visual symbols with sounds with abstract ideas.
Reading tarot is, in a lot of ways, is just the same. You have 78 cards with distinct images, and each card has a range of meanings attached to it - the exact details depend on which system(s) you follow, whether you read intuitively or whether you are deep into studying historical esoteric symbolism or whatever, and so on. In any case though, its a recognizable system with widely applicable card meanings, and as you get more experienced with working with the cards, and more familiar with them, the process of eliciting messages from the cards becomes easier. When you first start off, you draw a card and look at the picture, and maybe you have some vague concept of what it could maybe mean, but you aren't quite sure, and so you check in the LWB or whatever book you have, and you read the keywords and then you kind of stumble along, in broad strokes, trying to make some kind of connection that makes sense to you. The image and the abstract ideas are still separate and you are trying to bridge that gulf.
Which brings us back to the idea of why so many decks? If you have a deck with which you have grown familiar enough to have that kind of connection, isn't that enough?
Besides that, decks draw on all kinds of influences - each other, early 20th century occultist groups, ancient mythology, various cultural practices, astrology, numerology, qabbalah, various animal groups, whatever, and they do so in various ways and proportions and so, having many decks can also be a nice way to become at least a little bit familiar with other ideas or systems or whatever which for me - well, more learning is always, always a plus.
And so that is my overly long explanation about both what I think tarot is and how I justify spending all kinds of money on tarot decks when, one might argue one or two would be more than enough :D