Dictionary class lacks the very basic function ?

I want to use Dictionary class like this:

textboxM.Text = oMyDict.GetValue("textboxM");
textboxN.Text = oMyDict.GetValue("textboxN");

Where my dictionary contains the list of values for my textbox based on
the textbox id.

But it doesn't have it !

TryGetValue !? What's that ? Why I have to provide an out parameter,
isn't more simple just return the value or null if not found !?

.