where to start with text adventure

I'm pretty new to programming with C++. I went through a whole book on C, and I understand a lot of those concepts, so I'm chugging through this C++ stuff pretty fast. But I'm wondering how much I really should know before I could make a pretty decent text adventure game.
I guess I'm just not sure where to start, because I don't know exactly everything involved in making this type of game, and I'm pretty sure there are ways to do things that are much better than the ways I'd think to do them. All I know so far is how do use functions, looping, conditional statements, file I/O, and pretty basic stuff like that. I also know a little bit about structures and have a limited knowledge of text parsing (in C). I'm getting into enumeration right now.
So should I keep learning until I have a good understanding of classes and objects before I try to make a game, or is it possible to do something halfway playable with what I know?
To give you a better idea of what I want to do with this game, I want to have a 2D, maybe 3D map system, some kind of inventory, and then just locations and events. You can do certain stuff with certain items, there will be people to talk to, and possibly certain events can trigger other events. Nothing too complicated.
Thanks everyone.

I made a post on roughly the same thing. It's right below yours. I got some nice responses, so read those for info.