Why check box is checked after postback
<p>I have next code,</p>

<pre><code>&lt;form id="form1" runat="server"&gt;
&lt;asp:Label runat="server" ID="Label1" EnableViewState="false" /&gt;
&lt;asp:CheckBox runat="server" ID="Check1" EnableViewState="false" Checked="false" /&gt;
&lt;asp:Button runat="server" ID="Button1" Text="Button1" /&gt;
&lt;/form&gt;

protected void Page_Load(object sender, EventArgs e)
{
    if (IsPostBack) return;

    Label1.Text = "Label value";
    Check1.Checked = true;
}
</code></pre>

<p>Why on postback text is despairing but check box still checked ? 
Thanks</p>
