Many, if not most, of us dream of retiring early. It does have obvious benefits, such as gobs of leisure time to finally do all the fun things we haven't been getting around to. But there are also plenty of valid reasons to not retire too early. Here, for example, are 10 reasons not to retire before 66 -- the age at which many people are expected to retire, per the Social Security Administration (SSA).

For those born between 1943 and 1954 (i.e., those between roughly 62 and 73 years old), the SSA has assigned a "full" retirement age of 66 . That means they can receive their full retirement benefits beginning at that age. For many other people younger or older than that, 65 or 66 or so is a common age to think about retiring at, and many are aiming earlier. Let's review the disadvantages of that.