Old password not being accepted when attempting to change password I was trying to change my password from System Preferences on my MacBook Pro. I followed the procedure by filling in the old password along with the new one. However, I am informed that the old password is incorrect! I tried several times but it didn't succeed. The old password is not working so the newer one is not being set.
You can reboot into recovery and run resetpassword from Terminal to reset your password.