Bitcoin is a great investment but even the best investments can lose money if your timing is wrong, if you bought when bitcoin was 1000+ then even now you are still in problems if you timed your exit right you secured a good profit, so while bitcoin is in my opinion the investment of the century, you still need to use your common sense.
Absolutely you are right, in trading right time decision give you profit, otherwise the good chance never come back again, also it doesn't matter what you have coins enough or less, i am talking about the right moment, and only one moment give you profit, and if you left it so it has clear mean you should have to wait, and may be the time never come back.