I noticed after I rooted and flashed BB.4 My phone had completely wiped. Had to do the *228 to program the phone and all that.
Made a backup.
After making some tweaks, themes, kernels, etc. for a few days, I used SPrecovery to restore back to the original BB.4 install.
However, After rebooting, and putting in my gmail account, I turned on wifi... and found that my phone remembered my home wifi settings and password and was already connecting.
Why did this persist through a restore? Yes, I wiped data and cache three times.
Is doing an install from update.zip on memory card more thorough?