I have only been practicing Aikido for about 7 or 8 months now and I have allready noticed a drastic change in my behavior. I use to be more prone to fighting, whether it be verbal or physical. And now I use a more Aikido approach I think. I would rather resolve it peacefully than create more of a conflict just because I am angry.
In terms of the becoming more accepting of pain. I really haven't found much of Aikido to be painful at all so I have had no reason to become more accepting of it. I loooove the feeling of ukemi, but I don't feel pain from it.