Clojure ampersand weirdness

gistfile1.clj

; REPL-y 0.3.2, nREPL 0.2.3
; Clojure 1.6.0
; Java HotSpot(TM) 64-Bit Server VM 1.7.0_21-b12

(let [& 1] &) 
;=> 1

(let [[&] [1]] &)
;Exception Unsupported binding form:   clojure.core/destructure/pb--4583 (core.clj:4103)

(defn f [&] &)
;CompilerException java.lang.RuntimeException: Unable to resolve symbol: & in this context, compiling:(/private/var/folders/xz/d8ctt91s5n51kbwcb01z1m740000gn/T/form-init1123058310639178637.clj:1:1)

(defn g [&] 1)
;=> #'user/g

(g 1)
;ArityException Wrong number of args (1) passed to: user/g  clojure.lang.AFn.throwArity (AFn.java:429)

(g)
;=> 1