I want Class to remember the old values but it updates them :(

gistfile1.cs

class TheClass
{
	public int Val1;
	public TheClass Old;
}
class Program
{
	static void Main(string[] args)
	{
		TheClass aClass = new TheClass();
		aClass.Val1 = 5;
		aClass.Old = aClass;
		aClass.Val1 = 10;
		Console.WriteLine(aClass.Old.Val1);
		//Prints 10, not 5:(
		Console.ReadKey();
	}
}