Hare krishna dear devotees. When we remember our past lives we will have a lot of experience and this experience will not allow us to make huge mistakes which we generally make in our lives due to lack of experience. Experience of life is both good and bad. Both experiences are valuable and teach us all a lot about life. So we should not say that lord made us forget because we might get scared of what sins we did in past lives. Also if we remember what sins we committed in the past birth we will surely be not repeating those mistakes and finally we can return back to godhead. Why do we need to start everything from the beginning again?