I used to think that too, that we were going too fast, but I realize now that there is far too much in one technique to learn it in one or even three sessions. Though the basic motions may seem simple at times, there is a ton of subtlety in each movement. I remember learning ikkyo and thinking "Oh, okay, I've got it now." Then a week later we'd practice ikkyo again and I'd realize that I wasn't getting off-line enough. Then the next week I'd see that I was losing my extension.
The bottom line is that while you may want to just get it right the first time there are many concepts that are foreign to non-aikidoka and only through the practice of many and various other techniques will those concepts become clear. I thought I had kotegaeshi my first month, but it wasn't until months and months later that I realized I was doing it all wrong... from just one little thing. Heck, I'm probably still doing it wrong, or so I'll more than likely discover in a month or two. And I've been practicing a little over a year (not that that's a long time either).