Preparing for something inevitable is a no-brainer. With a bit of preparation and backup you will be more comfortable and ready for any eventuality.
You'll need to do your homework on a few fronts:
1. financial security
3. physical comforts
4. mental stimulation
5. social outlets
And the list could be quite lengthy. Most of our time will be spent on financial security first. Without a source of steady income retirement will be dismal.
You don't need to retire to enjoy "the retirement lifestyle". You need to identify your priorities at this time of your life. Take long weekend vacations to destinations you might enjoy. Spend more time with your interests. Cut down your other obligations. Tell the kids you'll be building your nest egg and they need to be more responsible with their finances too, since you can't bail them out anymore.
Travel the world. Don't wait for time. Make time. If there is one thing we wish we had done more is just that. We could have done it too.
Take classes, in whatever you want. The more hobbies and interests you can pursue, the more interesting your life will be.
As a matter of strict financial perspective, the longer you work, the more secure you will be, the more money you can set aside, the fewer obligations you will have to contend with in your golden years. Financial advisers (certified and fee-based) will guide you toward financial security at a time when you can put aside more money and need fewer goods to get by.
Don't wait until you're in your fifties. Do it today! At whatever age you are. Every dollar you put away will grow and be available to you those days when you cannot work anymore.