;; although negative (or zero) drop-item-counts are accepted they do nothing
(drop -1 [1 2 3 4])
;;=> (1 2 3 4)
(drop 0 [1 2 3 4])
;;=> (1 2 3 4)
(drop 2 [1 2 3 4])
;;=> (3 4)
;; dropping more items than are present is allowed, and all items are dropped.
(drop 5 [1 2 3 4])
;;=> ()