Is it normal that i started cursing lately?

I was never one to curse at all. I was literally able to go through months without ever even feeling the need to curse. When it came to cursing, I was too much of a goody-two-shoes to do it. I felt weird even saying a curse word. For the past few days though, I've been cursing quite liberally. I guess it started because I always have to deal with my little sister, who is almost 10. She's a real pain in the ass. She's the type to whine, cry, and kick walls when she doesn't get what she wants. It has been happening for so long now that I got so fed up with it that I reacted by cursing. What I said was, "There always has to be some kind of shit going on here man!" I felt good saying it. I guess it gives me some sort of release when I curse, so I do it freely now. I spent most of my life without cursing, so I started wondering about it now.