Regarding your edit to Christopher McCandless, it was removed because (as the comment stated) it included much commentary and little verifiable, cited content. As you know, anyone is welcome to improve Wikipedia, but there are guidelines that users are asked to adhere to. You are encouraged to read about the process of editing, perhaps by clicking on this tutorial. You might also check out citing sources. Editors are encouraged to put in content themselves rather than lobbing stuff into an article and hoping someone else will clean it up.
Welcome to Wikipedia - we need people who are interested and informed. If you have information and expertise to add - within the guidelines - then you are encouraged to be bold!