There are persons that may have been unlucky with the timing, but I have found that most people that miss the timing are those that do day trading, those that buy and sell their bitcoins on a daily basis, those that just buy and hold for months are able to ride the wave and to have profits.
to me i think no one can be perfect, i think every one must have missed the right time to buy or sell. i my self missed the right time for so many times, but still i am happy with my decisions as i have made so many bitcoins from trading while buying and selling on right time.