OnCreate and OnNewIntent both Called When Destroy activity is checked in developer option

There is a developer option in android-Destroy Activity as soon as user leave it.

So When i check that activity and run my launcher activity having single top flag.I have seen that both my onCreate and OnNewIntent was called when I launch app after pressing Home Button.

Can Anyone explain that why both the functions was been called and also It was called only for my launcher activity .Rest all activities were working fine.