Dear big brother Steven,
thanks for sharing your heartfelt story. I do believe it is a luxury as well! About surviving : some people use the diary as a means to survive mentally.
I remember seeing flashes of Settia's mum diary which she's kept since Khao I Dang.
I want to stress that it's never too late to start a diary, but it's a truly personal choice. If one doesn't, because it doesn't work for them, that's fine too. The act of logging life can be through photographs (instagram/facebook/snapshots on your phone or camera) as well, or posts on Steemit. Sometimes you have your partner who functions as the witness of your life :)
The act of self love is for me the most important aspect of keeping a diary - essentially just talking to myself and taking time to spend time with myself. Other people do it through exercise, meditation, creative work, etc.
Just sharing my two cents of the benefits of keeping one :)
One love!