A couple of things. First, if this isn't the first time, then it's a habit you need to break. Second, you need to get help from your direct supervisor. If you are in the habit of missing deadlines, your boss is in the habit of letting you, too, and you need to work on it together.
I suggest that you go to your boss and explain that, after missing this deadline, you realize that you have a problem that you need to fix. Point out the other deadlines that you have missed as well, and ask for help fixing it. Then listen.
Be careful not to come in with a fixed agenda, such as here's what I have done, here's how I'm going to fix it, etc. You need to have ideas about what to do, but you don't want to sound like you're doing damage control. Wait for your boss to ask you what you intend to do about it, and then explain that you don't like repeating your mistakes (as you have done), and what ideas you have to keep yourself from repeating them.
If your boss starts in with reprimands, keep in mind that you are working to solve a problem together, and once your boss is done, bring the focus back to that. It's certainly good to say that you're sorry for any problems that you have caused, too.
We all do stuff like this. I'm naturally absent-minded. (My parents were both professors, and it rubbed off on me. Not all professors are absent-minded, of course, but my parents were certainly part of the reason that they have that reputation!) I had a position in IT change management, and one of my responsibilities was to put emergency changes through by 4 pm every day. I lived in fear of forgetting this, and one day it happened. Three emergency changes got posted, and I forgot to send them through to get pushed into production.
My boss pulled me into his office and explained what happened, who I had inconvenienced, and exactly what inconvenience I had caused. I apologized, and he asked me what I was going to do about it. Well, said I, I'm going to have to make sure that this doesn't happen again. "Well, how are you going to do that?" he asked. I had to sit and think about it.
It didn't take long to realize that I was irritated at people who put through normal changes as emergency changes because they hadn't gone to the trouble of putting them in through the normal channels, and that this was my passive-aggressive way of acting out that irritation. The individual who had put the changes through never did that, so obviously my anger is misplaced. I told my boss this, and said I would have to apologize to her personally and find a better way of dealing with the problem. My boss was quite happy with that, and I started addressing the problem more directly. Interestingly, that was the last time I forgot to put emergency changes through.
Now, I'm telling you this story because you may be doing something of the same sort of thing. (You may have entirely other reasons, of course, but you do have reasons, and you don't seem to be getting at them yet.) You might do a bit of soul-searching, asking yourself why, deep down, you're missing deadlines. If you come up with some reasons (and you probably will) then share that with your boss — again, if asked. But, I've found that once I understand the underlying emotional reasons for and thoughts behind the behavior (and there always are some), it's much easier to correct. New ideas ("changing your mind," if you will) bring about new behavior.