TextWatcher вызывается, даже если текст установлен до добавления наблюдателя

in an android activity, i first recover the text in an EditText and add then a TextWatcher to it.

private static int WC = 0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.e("TextWatcherTest", "onCreate:\t" +CLASS_NAME);
setContentView(R.layout.main);

EditText et = (EditText)findViewById(R.id.editText);
Log.e("TextWatcherTest", "Set text xyz");
et.setText("xyz");

et.addTextChangedListener(new TextWatcher() {
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) { }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
    @Override
    public void afterTextChanged(Editable s) {
        Log.e("TextWatcherTest", "afterTextChanged:\t" +s.toString());
    }
});
}

but when i run the activity, the afterTextChanged method is called even if the Watcher itself is added after setting the text. so the log output is something like

onCreate:    LifecycleMain
Set text xyz
// screen rotation
onCreate:    LifecycleMain
Set text xyz
afterTextChanged:    xyz    2

the counter in the TextWatcher shows that the watcher that is called is the one that was added AFTER the text was set in the EditText. any ideas why that happens and how i can prevent that?