There are many reasons why one should consider purchasing travel insurance.  When purchasing insurance it is advisable to find out if the cancel portion is for medical reasons/death in the family only, which also usually includes trip interruption, trip delay, and lost baggage. OR, a "no fault" policy that covers cancellation for "any" reason including "forced" changes, emergency medical transportation, a collision damage waiver for rental cars, travel delay, lost baggage, trip interuption, and also for "price protection" which covers you for air increases or hotel rate increases when the rates are recalculated.

The "no fault" type of insurance is preferrable and is usually less expensive than regular "medical" insurance for cancellation. Many tour operators and travel agents offer this type of insurance. The only thing it doesn't cover is changes that you voluntarily make, in which case, your trip would be repriced at the current prevailing rates.

"No fault" insurance usually must be purchased at the time of booking. Other policies that cover medical, trip interuption, baggage delay etc. and only allow cancellation for medical reasons or death in the family can be purchased after booking.

Whether or not a traveler needs insurance like this inspires much debate. Considering that "life happens" and many a traveler has had to cancel their trip at the last minute, are injured while traveling, have a medical emergency, find out their flights have been cancelled or changed, or just simply have a bad hair day and don't want to go.

When booking a trip, consider the money you're spending, whether or not you can afford to lose all or part if due to unforeseen changes in your plans, and if the risk seems to be high enough, make the purchase.   One should read any insurance policy carefully and ask questions.  Then have a great trip knowing you're ready for practically anything!