This is like the 10 profile that I have created for SAP. Why can't I just create one and take it with me from site to site.

I am so sick of creating new profiles I just created one about a month ago for the exact same site. I took note of all the information but now it doesn't work. Every SAP site I go to I have create a new profile. Why is this? Why can't I just use the same id at all of your sites.