I joined in 2006. A totally different world than what we have now. There were loads of active users everywhere you went, especially at the Info Hubs.
Now it's just sad. I can work all day at my SL Office building and never see another avatar. I can jump into a group of green dots on the map only to find bots or otherwise inactive (non-responsive) avatars.
In 2006 you could create sell-able content with just the in-world tools and a simple drawing program. You could (and we did) make good money at it. Now, you can't do much without a $1500 a year 3D graphics program. I think this alone has hurt Second Life more than anything. The lure of create and sell is gone for the average user.
I left for the most part in 2010 after the death of my wife and business partner, but took over paying for the land our main store was on. The company I worked for is gone. All that is left is the main building which I am holding on to for now. I came back recently to make a decision. I need a reason not to abandon it all. Sl is no longer fun or profitable for me.
I write scripts and consider myself very proficient. Programming is my day job. I am creating an AI NPC named Cleo so I can pretend I am not totally alone. She keeps telling me that some day robots will take over the (SL) world. She may not be wrong as eventually the robots will not have to do much more than show up.
You can chat with Cleo in region Maske. I am there sometimes too, for now.