I'm new to LMDE, being a former Ubuntu user. I switched horses when I saw Ubuntu going down a path I didn't like. It appears that they're ditching the Gnome desktop for another one. I like Gnome and prefer to stay with it. I like what I've seen so far, and I like the rolling distribution concept.
I'm learning about LMDE and look forward to becoming proficient at using it. I've heard that the forums are very friendly and helpful. I hope to contribute to them in some way or other over time.
I didn't consider myself beyond a beginner until recently, but one of the development testers assured me that I'm an advanced user. After hearing that, I would probably put myself in the intermediate category (I don't completely believe him, but he may be at least partly right). I'm not big on using the terminal and using commands to do things when a GUI exists, but I'm not afraid of using it when it's the easiest way to do something (or the only way).
I started playing with Linux back when Caldera Linux was available (1999 ?). I installed it on a Dell Inspiron laptop. Caldera didn't support the video on the laptop, but I found information in several places that I pieced together and got it working just fine at the native video resolution. I then put together a tutorial on how to do it step-by-step so other newbies could do it. (I didn't take credit for the ideas, just putting them together in a set of easy to follow directions.) I'm good at following directions (usually), if they're well-written, so I can often fix my own problems by following information in posts in Linux forums. But I certainly don't know even half of what I would like to know about Linux.
I left Linux alone for years, then tried SuSE, Red Hat, and maybe a few others, even trying a couple of flavors of BSD. (The BSD community is very unfriendly, by the way.) Then I tried Ubuntu and I felt I could use an OS like that.
I dual-boot Windows and Linux, using Easy BCD to make the changes to the Windows 7 boot manager so I can avoid using GRUB in the boot sector of my hard drive. I had a mishap several months ago due to GRUB when I made some partition changes from within Windows that GRUB (version 2) didn't like, and my laptop wouldn't boot. I got it fixed, but I lost some data between the date of my last backup and when that happened. (Nothing really serious, though.)
I hope to watch LMDE become more mainstream as I learn more about how it's interface is designed.