Well, no, you haven't. You just spent sixty bucks on some plastic and foam in the hopes that it will help if you fall over. "Doing everything you could" would involve a motorsports helmet, an intensive course of bike handling training, and staying off public streets while riding. The fact that your helmet is giving you "confidence" should be a warning flag -- are you sure you're not more likely to need it now?

The point, for the OP, is simply to keep in mind that despite all the "My life has been saved a dozen times!!!" foolishness printed at BF, a helmet is not a miracle. It is not likely to help when run over by a car or slammed into a light post, cannot protect against massive facial injuries or spinal trauma, and is no substitute for skilled and cautious cycling. And no, spending more money does not necessarily mean that you are "safer".

The best advice is to avoid falling off your bike, and again despite the "you never know when it's going to happen" rolling victim BF crowd, bike-handling skill can be developed and does make a difference.

</rant>

PS. I ride with a helmet about 95% of the time, because something is better than nothing -- as long as you're not under the impression that "something" can really be counted upon.