Back in January, I read Ann Voskamp's book, 1000 Gifts. She talks about the importance of giving thanks, as the book grew out of her resolve to start a journal of things she was thankful for, and found the practice renewed her heart.
I've begun practicing what she talked about, keeping a journal of things I'm grateful for. I'm only at 106 but the practice has made a difference in my heart. I do feel more cheerful, more at peace. In some ways the practice feels artificial, I could in one blow arrive at billions upon billions (all the subatomic particles in the universe God created). So I list things, ignoring the question "why this thing and not these others," and feel blessed in the listing.
You don't expect a book on thankfulness to plunge you right into the depths of human tragedy, but in the first chapter she describes grieving when her young sister was accidently run over in their driveway, and also a brother-in-law losing two young sons to a rare disease. But those tragedies are what drove her to wonder about life with God, what to do when it isn't at all a "I met Jesus and now life's wonderful" story.
I'm reminded of a favorite quote from years ago. Aleksandr Solzhenitsyn in The Gulag Archipelago talks about his coming to faith in God in Soviet prisons, and concludes the chapter with "Bless you prison, for being in my life." He came to be thankful for the hardest thing in his life, because God brought blessing in it.