Welcome to the group! It's normal for most guys to have to reshave the back and lower sides because that's where hair is the strongest. I usually shave WTG on the entire head then ATG. After the ATG pass, I feel my scalp and depending on how long it has been since my previous shave, I lather and reshave the back and sides. However, since I started using the shaving brush, one WTG and one ATG pass is usually enough. Check out some of the threads, they offer some good tips. Good Luck!