Why do we lose things, before finding them in a place that we've already checked?Watch
Because when you're looking for something, especially when it's next to a lot of clutter you tend to glaze over the total objects rather than look at each specific object. I'm sure if you had 0 objects in your draw and looked in your draw, you'd see your keys.
Makes sense. Really, I'm not sure why I posted the last couple of threads. Anyway why is our body so adept at fighting disease and doing all of its 'things' yet we have never evolved a brain capable of properly retaining information - which would be a necessary survival requirement.
In regards to memory, the brain actively filters out what it thinks isn't important or worth remembering. It's called stimuli and our brains block out a portion of incoming stimuli, it has to for us to keep our sanity. For example right now as you're reading this comment, you're probably sitting in a chair, looking at a monitor, which is on a desk, which might have objects on them etc but you don't process this information... those objects are there and even when you use them you don't actually acknowledge them, that is because your brain doesn't see them as important.
There is a mental illness called low latent inhibition where your brain doesn't block out the "clutter" stimuli and you process everything. People with a high level of intelligence can handle the stimuli and will most likely become extremely creative, perhaps even a genius. Those with low or average intelligence will most likely spend the rest of their lives doped up on pills and in a psych ward because they just can't handle the extreme amount of information.
I hope this sheds some light on why the brain blocks out junk information.