I was watching the Paralympic closing Ceremony, and it was absolutely lovely (for those who haven't seen it, go see! It's druidy). The main speaker reads from a book and I was thinking about that. There is a big push in a lot of circles to memorize everything said in ritual (or speak from the heart...but either way it's sans book). There is a lot of reasoning for this, but I think that a proper speaker can make a read passage wonderful.
I'm a memorizer. Have been since gradeschool when I had to memorize poems (which I can still recite: Jaberwocky and Stopping by Woods). Once something is locked in my brain it becomes a part of me. I like the fact I don't have to run and find the book I saw something in to reference it. When it comes to lyrical or poetic pieces, I love being able to just ramble them off without a lot of thought.
I recently got into chanting, and that is so much fun. I think that chanting really illustrates the power of memorization. You don't want to have to think about what comes next in a chant. To really get into it and feel the chant, it has to become a part of you, something you just are and can do. The words flow out of you and you don't have to pay attention to them, they just are.
My memorization process is essentially two-fold. There is an initial period of learning. In terms of a spoken thing, I say/chant/sing it while looking at the lyrics. I do this typically as many times in a row as I have time for. I don't try to remember what comes next, I just read the words as they come and try to keep the flow going. Sometimes I'll put songs on repeat on my computer so I listen to a grouping over and over for several days. Step two is a bit counter-intuative, but has been part of my learning process since high school (or at least that is when I figured out it was part of my learning process). I walk away. I go on and do something else and don't try to think about it for a while. Almost always, after a couple of days, I can recite whatever it is just fine and a lot more naturally than I could before that resting period.
It's a little different for information, though the immersion-rest cycle is similar. When I start trying to learn something new, something that I know I'll want to remember without having to go look it up, I go through an intensely obsessive period where I read everything I can get my hands on. I'll have multiple tabs open on my computer so I can compare different pieces to each other or look up stuff that one resource references. Writing is an important part of my learning process too. I find I learn and remember better if I work on making my own copy of the information, putting it into my own words or combining different ideas into a cohesive whole. The more involved I can get my brain, the better.
What I struggle with is seeing a project through to the end. My attention span is quite spastic, so sometimes in the middle of working on something, I'll get drawn in an entirely new direction. I'll end up on a whole other project before I realize I've left the first one, and it can be years before I get back to what I started. What I find though is that I often retain a lot more than I thought I would, sometimes I'll get asked something or try to explain something and realize that I have a broader understanding than I would have said I had.
But back to memorization. One of my favorite quotes is from Indiana Jones: "I wrote them down (in my diary) so I wouldn't HAVE to remember them." There are some parts of my practice that I feel are key. Concepts that are so integral to the workings of everything else that if I didn't have them memorized I wouldn't be practicing anything, just doing random motions that had no meaning. The elements and their correspondences (in general) are one of these things. I never have to look in my books to remember what colors go with which quarter, or what the elements represent. If I go obscure enough, then yes I do have to look stuff up (I doubt I could tell you what choir of angel is associated with east of the top of my head). But that is why I write down stuff that interests me...so that when I want to find it again, I have it.
When I first started practicing, I had some pretty hefty Wiccan (in the mass published sense) influences. The charge of the Goddess, the story of the decent of the Goddess, the great rite...these all have wonderful spoken bits, but weren't things I used often enough to memorize. The Wiccan book of Law is waaaay too long to bother with (though I did hand copy all ten pages of it). I have copies of various Sabbat rituals with full spoken texts that I think are pretty, and if I were ever to perform those particular rituals, I might memorize the bits I was supposed to say.
The one drawback I find to memorization is that things that become rote...become rote. It is really easy to slip into automatic drive and say the words and go through the motions without engaging the deeper mind. I did some work with the LBRP (lesser banishing ritual of the pentagram), and I don't know if it was the daily repetition, the resonating of the letters, the angelic imagery or what, but I found it hard to really commit to it. I would catch myself, saying the words and doing the gestures and whole sections would have passed and I didn't really remember more than that I had done them.
So, to memorize or not to memorize....I guess for me it depends on what I'm doing. Some things I am definitely drawn to memorize and not have to look up. I am always looking for new sources of information and impressions on runes because divination is definitely in the "don't want to have to look up" category. It just kinda blocks me if I have to go looking through a book to find out what something means. Chants are definitely in the memorization category (as are songs). Most of everything else falls into the "whatever my whim leads me to do", sometimes I'll feel the need to memorize stuff, sometimes I'll feel the need to just copy it down and not really internalize it....and sometimes I'll think I'm just copying it and will find it cropping up enough that one day I realize I remember it without having to go look it up.