Good for you! You have taken the first step in getting your BSN by looking at different programs.
I just graduated from a RN-Mobility program in December 2001, after starting the program in August 2000. I had already taken several prereqs over the years, so I had 4 to complete after I officially started.
Look at all of your options, including internet options, as pre-req requirements vary greatly from school to school.
My program gave 32 semester hours credit for my original nursing school program.
I cleped out of English 101, but you probably took that in your ADN program. Check with the admissions advisor at the school you are looking at -s/he should be able to tell what what CLEP exams would be appropriate for you.
As far as forgetting your adult nursing stuff--that should not be a problem. All of my previous experience is maternal-child - L&D, neonatal ICU and OR, and not being familiar with adult medical care was not a disadvantage at all. Upper level classes at my school were - research, statistics, community health, management, health assessment and promotion, pharmacology and cultural-spiritual nursing. Like precious nurse said, my program was mostly papers and presentations, not lecture and tests.
Going back to school was a struggle, but it was well worth it - you will meet new friends, make useful contacts, and gain better writing and presentation skills, as well as gaining self-confidence.
So go for it and good luck!