I was generally a happy drunk, or at least a quiet well-behaved drunk, but based on what I see in myself and friends/family, it doesn't make much difference. It's more the issue of crossing over that invisible line into addiction, and the big picture of the negative impacts over time.
As for the person who questions their drinking versus the person who never thinks it's a problem ... I think the one who starts questioning is the lucky one. There's a common saying, that the addiction elevator only goes one way (down), but we can get off at any floor. We don't have to wait for it to get worse.
My sister and I had similar drinking problems. I questioned it, and two years ago, I quit. My sister rarely questions whether she might have a problem, and she's still on the elevator going down.
So I think I'm just really fortunate that questions arose in my mind, and I got to get off the elevator.