I've just recently realized what my particular issue was with all this. It just made no sense to me that something that just came so simply and easily to my kids could possibly be not as simple or easy for other kids. The thing is that my friend probably does more stuff with her girls than I do with my boys. They have at least as many opportunities to soak up information, but they just don't do it the same way my two do.
I have kids who are different enough from the kids that are the norm for the charts that it was hard for me to accept that it was my kids that were different and easier for me to accept that the charts must be wrong. It actually took me quite a bit of time and emotional stress to come to terms with it. I really had to adjust a lot of my preconceived ideas about how my life with my kids would be because of it.
Not that this is what you are going through, but when I read your post it reminded me SO much of that time in my life that I felt I should share my perspective...
Wow, you couldn't have said what I feel/felt more perfectly Wyldkat!