Poss trigger suicide and death of loved one

I was just thinking this some may find interesting. Feel free to leave your thoughts. The reason we cannot go back in time (why we are in a universe without such known device, so far). Is that b/c if we could we would try to fix these sticking points in our history and relive the awful days over and over trying to make everything perfect. We would never heal or move on doomed to repeat the same experiences destined to happen. I could try to save my friend from killing himself but it may have happened anyways a different way at different points in time all leading to sadness. Having all these images in my head over and over where I can't save him. Growing old and dying trying to prevent his death. Sorry this got so dark there. So we move on one day at a time. Forced to live with our choices, mistakes, and dreams. We look to a better future b/c there is no changing the past. I used to hate this notion but maybe it's a safety feature that God or whatever higher power you believe set in place to protect us from ourselves. May you all find your happiness in the past, present, and future.