system
surprised: My utility bills were lower than expected this month, so I was shocked.
human
A bit unexpected but nice: my utility bills were much lower than expected this month.
gpt
Right on, glad to hear it. I hate utility bills and how unexpectedly high they can be. I especially hated living with roommates who didn't mind getting them really high, just for the sake of having it a little cooler.
human
Yeah I agree. You never know what it will be each month. I expected it to be higher this month due to the increase in A/C and fan usage, but actually wasn't bad. 
gpt
I hope it stays that way for you. Luckily I'm in an apartment now where the utilities are included, so I don't have to stress about what it's going to be, or confronting my roommates.