Is it normal that i apologize too much?

So, I'm not exactly the most confident guy out there. If anything, I'm socially introverted to the point where I just don't like talking to people because I'm self-conscious of what others think of me.... And I guess it's because of that that I tend to apologize a bit too much. I don't like making people (including strangers) hate me. If a person bumps into me while I'm standing in line, I reflexively respond with a "sorry about that." I mean, I don't mind apologizing as long as the person is not angry at me. You know, "Break bread with the enemy" (I got that from DMX :D). But there are times where I don't think I should apologize, but yet, I still do. (I know... I'm such a pussy).

Last night, I was driving in the Wal-mart parking lot when the car in front of me just stops. I didn't know why the car stopped but before I knew it, the car started backing up without warning.I guess he was waiting for one of the parked cars to get out even though there were ton of more space up ahead (I guess he just doesn't wanna walk). I looked in my rear view mirror to make sure nothing was behind me and backed up like 1 foot. Before I knew it,I found an angry Hispanic (not Mexican, because you know, not all US Hispanics are from Mexico) mother started banging on my window with her nails. She started yelling at me saying how I wasn't paying attention and I almost hit her daughter. I tried to explain to her the car was about to hit me and I didn't see anything behind me, but she cut me off saying "It doesn't matter, that's a machine, she's a human." I admit, that's a good point, but still I wanted to argue saying it wasn't COMPLETELY my fault. It's still think it's my fault, but other people and factors are to blame too. I mean, it's dark at night and her daughter is like 2 feet (possibly a 2 or 3 years-old), so it's hard to see something so small behind my car. The car in front of me was backing up without warning. I especially wondered why the toddler was behind my car and not side-to-side with her mother. I wanted to tell her all those things, but I just quickly apologize, saying "I'm sorry, it's my fault" on a reflex. Even when she walked off, her toddler was walking behind her, not within her mother's sight which kind of pissed me off. But in the end, I was mad at myself for just apologizing and not justifying the blame on the driver ahead of me.

So with all this wussy talking.... is it bad I apologize too much?