I don't want to offend anyone here, but in my opinion, there is no reason to ever forget the gear. Whether you have a working gear warning system or not, it has to become part of your pre-landing checklist, written or mental. For example, I do a GUMP check at least 3 times during a normal pattern. In fact, I always say it out loud. The last time I do it is after I've turned onto final. I say out loud "gear is down" and then say "heels on the floor" to make sure that my feet aren't on the brakes (but that's a different issue). I know that some have said that when you're doing a simulated engine out, you tune the warning system out, but a thorough mental checklist will remind you. Yes, there are times, especially during an emergency, when the pilot becomes distracted, but training yourself to say "gear is down" on final will remind you to check the gear. Of course, don't just say it. Check it!! Again, I don't want to offend anyone who has forgotten the gear, but I don't believe the saying that "There are those that have and those that will." To me, that's putting a negative thought in your head that "Hey, I'm gonna do this eventually." Don't believe that bull. It's the same thing as saying, "Hey, I'm gonna eventually crash this plane, but it's expected." If you consistently perform the same checklist EVERY time you land, you can prevent this from happening.