Your answer to this question is probably not a whole lot, at least in terms of your investment portfolio. Some surprises may be great, like if you’ve saved more than you needed, but you could also be devastated by not planning for things like medical expenses. In The Wall Street Journal Glenn Ruffenach writes that retirees often find themselves in surprising situations, whether for better or worse.

The surprises ran the gamut, from the wonderful to the devastating. Many readers told us they were surprised that their savings are holding up just fine, although several said that household expenses—and Medicare premiums, in particular—have been steeper than they anticipated.

Relationships? Conventional wisdom holds that making friends in later life is difficult, but numerous retirees told us the conventional wisdom is simply wrong. They also told us, however, that they miss being part of a team at work, much more than they imagined.

Fitness and health? Far from turning into couch potatoes, many readers told us they are in the best shape of their lives. “I feel better than I have in years,” says William Wilson, a doctor who lives in Atlanta and Portland, Ore., cycles daily and has lost 40 pounds since retiring in mid-2015. “I sleep well at night now, too. What a treat.”

Most wrenching of all: stories of retirements cut unexpectedly short. “The biggest surprise has been mortality,” notes Richard Sandaas, a retired engineer and project manager, in Kirkland, Wash. “My wife took early retirement in 2003—and less than 10 years later passed away. We thought we had many years of postretirement ahead of us.”

Read more here.