I have read these are not as nervous when they reach adulthood, but how long is that?
That is true, they are much less 'feisty' when they are adults (about 2 years old). For us, the trick was making them get accustomed to walking on our hands in their cage (our cage for the four 'babies' is an 4' X 1 1/2' aquarium with about 2 inches of sand and rocks on the bottom).
We put our hands down on the sand, near them, and allowed them to smell us. Then we gradually handled them very near the floor so they can get away. This process takes some time, and it should be gradual so that they don't become annoyed by too much handling. We also have the babies cage in our game room (right by my PC desk, actually) and the couches and TV are on the other side of the room. I really think it helps to have them in a busy room of the house so they are used to noise and people.
One of our geckos, I swear, is determined to 'get' our dog...she wants to pounce on the glass to get at him, it is so funny to watch. I guess she doesn't realize that size DOES matter. IMO, it is also best to do the handling a couple hours after feeding.
The mothers cage is in my daughters room and I think she is more shy because of it (although she is fine with my daughter handling her).
They actually are very low maintenance, regardless of what the books say (about the perfect humidity and temp and all) as a matter of fact....
Years ago, we had a baby get loose (somehow jumped out of the aquarium) and was gone for
3 weeks...I found her in the game room (she had somehow gotten downstairs!!) Actually my golden retreiver alerted me of her presence!!! I think he was totally freaked out by it and didn't know whether to attack it or fear it!!!! Judging by the other baby that was born at the same time ...she had grown LARGER while she was enjoying free reign of the house....no food water bowl... (and this was in January)...So, even though they cannot climb glass, it is a good idea to have a lid (epecially if you have other pets)