i retired in October of 2011, Much of the time between then now was spent in finding the right locale for my retirement, moving in April of 2012 and getting things organized. But i have never once thought 'What now?' in terms of not knowing what to do with my time. It's more like prioritizing the things i need and want to do. (Always there's the bills and the chores---i've even got some new ones---stacking and moving Firewood into the house, building fire in stove and cleaning the ashes as needed during the winter, trying to get a garden going in summer). i worked one way or another from age 11 till i retired at 65, at a wide variety of jobs. They were to earn a living...they didn't DEFINE me. My artistic output--poetry, prose, photographs, repurposing of objects that have outlived their original use are what define me. And i finally have all the time i want for those things. i'm an organized person, so paying bills (the only thing other than feeding my furry companions that is a MUST and has a schedule to be met) takes very little time. That means if i get 'on a roll' creating...i can go with the flow...because most everything else can be postponed a day or two without any negative consequences.
But everyone is different...maybe your occupation and family (i was a single Mom most of the years my kids were young--i still made time for my creative pursuits) kept you too busy to find out what makes your heart sing (other than those you love)---what activities feed your soul. If you're in a committed relatiohship...your partner should be a part of your 'process'...they might be able to remind you things you've said you wanted to try. But also this can be a difficult time for couples if one person is 'changing/growing' and the other isn't. You need to find ways to nurture the relationship while also nurturing yourselves as individuals.
My short list of suggestions (a long one would involve asking questions about individual interests, talents, skills, joys) for those who have trouble filling their time with productive and/or fun activities:
Think about what has always given you the most joy PERSONALLY. Often it's the thing you may have felt guilty about taking time for when you were raising a family, because it was 'for' you yourself, not anyone else. Then indulge it.
If there's nothing that just 'calls' to you, you'll need to think about what activities help you feel good---about yourself, the world around you. If you feel 'bad' about yourself without some external role to define who you are...create a role you can feel good about---volunteer--with people, with animals (private 'rescuers' help match up a lot of homeless critters with loving families). Look thru the class catalog of the 'Outreach' division of nearest college/university---put a check by anything that sounds interesting---consider taking a class or two---even if the subject matter doesn't fulfill you...it might help you realize what would---and in the meantime you get social interaction with new people...anyone of whom might help you find what to do with yourself for this chapter of your life.
Travel--if you're not comfortable traveling alone find a 'travel buddy' ---if no friends/family interested---check out local senior center. Maybe someone who loved to travel but has some physical impediment to doing so alone now, would be willing to be your 'guide' in exchange for your help/companionship. For that matter many senior centers plan trips to nearby places of interest. (We so often overlook the interesting destinations in our 'backyard', our own vicinity.) Start with day trips to points of interest nearby you haven't seen (usually we tell ourselves---'Have to go there some day. Ah well plenty of time...it's right there, so close').
Write a family history---as a legacy for grands (even if you have no direct descendants grand nieces and nephews might benefit from knowing more about their ancestors. Scan your photo albums to DVD and make copies for other family members. (That's on my list---time consuming---but something i really want to get done within the next year or so.)
And you know, it is ok if you don't have a 'passion'---if you just are happy to not HAVE to set an alarm and be somewhere at a specific time fullfilling a function for others. It is ok to take some time (even if it stretched into the rest of your life) to just relax and enjoy whatever 'amusements' you enjoy (books/movies/communicating with other online). One of the many things my father said that has stuck with me is that there is NO excuse for an intelligent person to be bored. (Save maybe when you have to be in some boring meeting). As long as your daily life is not leaving you in a state of 'boredom', with that pacing caged animal feeling...it's ok if you're not 'doing' anything productive or creative as long as you're not ignorging 'must do' tasks like bills and personal hygeine. i personally cannot imagine living that way---even when my priority was my 'Mom' role i brought my creativity to that role in various ways. But that's the thing about retirement---it is not one size fits all...we each get to design the life that suits us here/now.
There are lots of 'find your passion' books, videos and programs out there---Google or Bing it. Or we could discuss here ways to that. i've always been a problem solver---good at asking questions to help people define the parameters of their 'problems' and then helping them find solutions that will work for them. And see that is yet another thing that 'fulfills' me---helping others...