This year Facebook's year in review feature--always treakly, usually irresistible--has come in for harsh criticism. People who have endured a challenging year resent the forced good cheer and painful reminders that this tool can provide. This is particularly so when Facebook aggressively promotes the year in review within people's feeds, showing pictures they do not wish to see again even before they activate the review.
My toughest year was 2009, when Helen and I divorced. Had the year in review come along then with a picture of the two of us, I too would have been hurt. And I am sorry for all of the people in 2014 who have been similarly affected.
One thing that may be helpful is to recall that Facebook is just a cash-hungry conduit of user data for advertisers. It is soulless more than heartless. That sting people feel is real, but it's not personal.