I don’t agree with that. It doesn’t matter if your past was glorified or not. Your present greatly depends on your actions in the present.
If you have had a great past, it will help
You build a good present future but it’s a very small part of it. Mostly its our present that decides for us.
I agree that's why they advice not to hold on to who you were in the past or what you have achieved in the past because it is the present that matters. Therefore you have to also be in the present and do meaningful things in the present. Although it's good to reminisce on the past don't stay there for too long
Past glories can make you relent and make you think you have achieved not knowing there are more to achieve in the future.
And past glories can also help you if you use it positively,it will encourage you to do more