I did stand up in early childhood, but never really managed to get the hang of it and eventually stopped entirely when I was around 8. I only started standing up again within the last 5 years, but it still doesn't feel right and I only do it when I have no other choice (I'm in the wilderness, all the stalls are full, or the seat is really filthy)
Also, I started wiping myself around the time I entered puberty. I just couldn't keep control the way guys were supposed to.
Actually, I never figured out why that was giving me problems; I'd always thought I must be defective or stunted or something because it just seemed to come naturally to guys while I was struggling with it. Now I'm realizing that doing this after the female way has been the norm for me and I'm more comfortable with that.