"What's the harm in having obscene amounts of memory, making my system effectively future proof?" Well, Aphrodite3D (2 posts back) beat me to it. But it's even worse. Say that you don't really need 12 of those 24 Gb ram. That's $149.5. Now, if you wouldn't have bought those 12 Gb and notice in 5 years that you really do need more than the RAM you already have, you probably could have bought more with those $149.5 than you have now. And, as Aphrodite3D said, technology marches on so it's possible that your RAM is outdated at that point in time. So, you need to buy all your 24 Gb again in the new memory technology, what makes those $149.5 completely wasted.