Changes in life
Not having to worry if I'll fit in seats is a huge one. Movie theaters used to be pretty risky, and airplanes were horrible. No problem now, though!
I never used to wear skirts or dresses, and I do now all the time. I love wearing colorful tights under them, wheres pre-op the only kind of tights I could squeeze into were the 4X size nude color nylons from walmart.
Dating. I know many people have very successful love lives at all different sizes and I absolutely believe in the BBW, but for me personally I was not even considering dating pre-op. I was desperately lonely and WANTED to date, but I felt that if a man was willing to look past how huge I was was already so far in his debt that it would never be an equal relationship. I also thought that men who prefer bigger women were weird and must have something wrong with them. NOW of course I can see that was just my own self-hate, and that there's nothing wrong with preferring bigger women, but at the time I was not willing to even try dating. Now I'm happily married to the man of my dreams!