Do you ever feel that middle-earth really exists?

[Numenorean]

i havn't seen any elves or trolls or balrogs around, or even heard of remnants of them

Me neither Maeglanthirion! But given that the Human Race (as we know it) has been around for what, about 20,000 years, it leaves a hell of a lot of time - some millions of years and more - during which thousands of unknown races, beasts, phenonema and living beings could've evolved, lived and then quite simply vanished from existance, through natural or other causes.
I know its only speculation, but as a race we know so little about the distant past that who knows for sure, I'm staying open-minded on the off chance theres something in it!