If you have a long time horizon and you are still contributing then market drops are your new friend. Everything goes on sale! Your dollars buy more shares.
Which would you prefer?
Markets goes up 10% per year for 20 years.
Market drops 99% in year 1, stays there for 18 years, and then just gets back to even in the 20th year?
Assuming $10,000 contribution per year.
Scenario 1: $572,750.
Scenario 2: $18,020,000.
In scenario two the last year requires 9,900% returns to make up for the 99% drop in year 1.
Market drops help you when you are still saving.