First, preemptive and preventive uses of force are often justified by claiming either that there is substantial risk of a future attack or that it is difficult to ascertain how dangerous the target is.
Short-Term Memory: Up to 7 Items, But Highly Volatile. Many psychology experiments have shown that our short-term memory can hold only a limited number of separate items. The average is about 7 items, plus or minus 2, depending on the individual. You can easily confirm this by reading someone a series of words that have no connection with one another, then asking this person to repeat them.
It is usually assumed that the short-term memory spontaneously decays over time, typically in the region of 10 - 15 seconds, but items may be retained for up to a minute, depending on the content.