I think it can happen naturally based on your lifestyle.
For me, I have stopped carrying Glocks and other passive safety guns due to risk of my own negligence even though I do follow the 4 rules.
I have a three year old in my house. When she was little, it was no big deal. Now she can get into everything. Please keep in mind that ALL of my guns are locked up. The ones in the cabinet are stored unloaded and locked. The magazines and ammo are stored in a separate safe using a different key (both of which there are only one of and always on my person). My nightstand gun is in a key pad vault which only my wife and I have the combination and has a lock out after 3 failed attempts. My daily carry piece is stored in a three digit combo nano vault kept in my truck, locked, and parked in my garage.
I feel that I had done a lot to keep my firearms safely out of reach of my daughter as well as constantly drilling into her head "if you ever find something sharp or looks like a gun...leave it alone and come get daddy".
That said, I'm human. What if I forget get to lock the bedside safe before I step into the shower? While it would be difficult for my daughter to get into it, I feel a lot better about having a pistol in there with a 12lb trigger pull and completely deadened by the safety. In short, it may take her a few minutes to figure out how to use it. A Glock? Well I have touched off a Glock on accident and ended up with a nice hole in my wall, 2 days or ringing in my ears, and left pretty shaken up. Totally my fault. I dropped the mag and didn't check the chamber. I don't normally keep it chambered and didn't remember loading one in the pipe after a range visit. Luckily it was pointed in a safe direction, but it would be even easier for a 3 year old to do terrible damage had it be left accessible.
As for my EDC, I prefer a revolver. Mainly because my day to day requires that I take my gun on and off my person. I don't like handling a Glock outside of a holster unless I plan on shooting it. Don't get me wrong. I love Glocks. I think they are fine and very safe firearms. They just aren't forgiving of accidents.
Just personal preference, of course.