You don't own objects.
TL;DR: don't use my as a name prefix.
Problems
Lack of context
Bijection Fault
Solutions
Remove my prefix.
Change to a role suggesting name.
Context
Several old tutorials use the word 'my' as a lazy name.
This is vague and lead to context mistakes.
Sample Code
Wrong
MainWindow myWindow = Application.Current.MainWindow as MainWindow;
Right
MainWindow salesWindow = Application.Current.MainWindow as