I used to be able to drink all night, now I just pass out. Is it because I’m getting older?

I don’t drink that often, maybe once a week, but after 6 or 7 watching a movie or playing a video game or something, I wake up on the couch like wtf. No issues with my liver or anything like that but I’m 40 now. Alcohol used to energize me now it knocks me out.