. >> reporter: marguerite to hopes oona's message of gratitude will sit with readers well beyond the i'd want to go back to if i lived that way. there was a presence of the now, which i found so profound weaved through the entire thing. >> and that was something that really came about organically. it's a lesson that i actually learned writing the book and it actually really made me much more at peace with turning 40 and just the way that i look at aging and being nostalgic or planning for a future hoping for, you know, that better tomorrow but meanwhile, the only thing we have is this moment. we have to believe that our best days can still be ahead of us. >> reporter: for "good morning america," sara haines, abc news, new york. >> thank you for that, sara haines "oona out of order" is available now. we'll be right back. ♪ i feel it coming ♪ i feel it coming, babe ♪ i feel it coming that could mean an increase byin energy bills.. you can save by setting your heat to 68 or lower... unplugging and turning off devices when not in use... or just letting the sun light your home. stay well