What you said here is true. No one really taught us how to deal with a loss, and that's probably why it is hard to cope when we experience it. Sometimes, grief makes one feel abandoned, which is even more difficult to accept. But yes, time heals.
It is not that time heals you as such, because even after so much time has passed, remembering the loved one causes a lot of nostalgia. Time teaches us what no one ever teaches us: to face and accept the most difficult and strongest moments of life, and it is as I say if we were educated without fears and we were told from an early age that death is a natural process in us and that it is inevitable we would accept it better, of course accepting does not mean that we will not be sad for a while mourning our loved one, but it would not be so traumatic.