Question: Why should one be afraid of being reborn in a lower realm like hell if one does not remember anything from one’s past life?
Answer: If one knows one is going to hell later, one will be terrified now. If one is in hell now, one will be terrified now too. Therefore, the true terror is more in terms of now and the future; not the past. Healthy fear is good as it leads to moral shame from doing evil; without which there will be more evil done.
Is Buddha able to offer an explanation why is it such that a person has forgotten his past lives when he is born in this life?
Thanks for sharing
When there is great trauma, the mind naturally blocks it. This is so even within this life. Rebirth is very traumatic, due to great pain and suffering at death and when (re)born.
Also, just as we easily forget what happened even just last week, due to our weak memories functioning through our weak untrained minds, especially when there are great changes in our forms and the environment, without familiar reference points, it is even easier to forget our past.
More on this phenomena can be learnt at https://thedailyenlightenment.com/2013/04/how-death-hinders-progress-to-liberation/ Amituofo