Do I really need to know XAML?

Is it really necessary that I learn to program in XAML, or can I safely rely upon tooling to handle the dirty work for me?  In the world of WYSIWYG form designers, is it really necessary that I understand the language beneath the form?  For example, if VS.NET were able to create a Windows Form for me today whose InitializeComponent is written in VB.NET, and I inherited that form’s class in C# to create my event handlers, do I really need to know VB.NET when I can manipulate controls and properties on a design surface?