Maybe it is not a math question.

I have got my math PhD degree fro more than 10 years, and my major is algebra. I have published some papers in some journals such as Adv. Math.. I really love math, but I am still think I haven't get a good and complete math education, and do not have a good picture of math. Someone may argue that I can teach me math myself. The problem is I am a teather in a university now, so I have to teach a lot of classes and have other duties. Now I have an idea which sounds crazy: I want to do another math PhD again. But the problem is I am  almost 40 years old. So I am wondering if there is soem kind of realizability? Does someone have such experience?