Advisor: ... and if you didn't stay invested you may miss the best months. Look:"
Poor Joe: And if I missed the worst months? What then?"
Advisor: ... so Buy-and-Hold is the best strategy. Even if you only missed the ten best days ...
Poor Joe: What are the chances that I'd miss the ten best days?
Advisor: ... so my advice is to stay put, ignore your investments ...
See Best, Worst and Market Timing.