Mmmm, I have two projects open in IntelliJ right now, one of which is quite large, quite a few tabs, and it's using 366mb of heap.

You have to watch out though - Java won't collect garbage if it doesn't have to. This fools a lot of people. They look at memory usage and assume it must really be using that much memory, even when it's not. From the perspective of the JVM if the memory is there, it may as well be used, because freeing RAM just to leave it pointlessly empty just wastes CPU time, battery, generates waste heap etc. Why not use it? The only time it matters is if you have something else that wants the memory and it can react to that I believe. Or if you're measuring it against other tools of course.

I guess over time this will go away as a talking point because the JVM is getting more aggressive at collecting memory even when there's RAM spare, partly because of containers and partly because of threads like this one.