Manipulating dropdown.selected index from c# - are 0 and 1 the same??

The official documentation (http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.dropdownlist.selectedindex.aspx) states that 0 is the first entry in a dropdown list, and indeed this works.  However it seems from me testing things that 1 is also the first, 2 is the second, and so on.  Is this really the case?  It seems crazy.

Bill
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