That 'it' refers to the speaker's lost mind (his or her mind is lost and nowhere to be found, but still the mind sends postcards to the speaker).
I guess
所有跟帖:
• so? -tern2- ♀ (169 bytes) () 06/01/2012 postreply 18:12:48
• hahaha I know, I am all talk, ha -youknowmyheart- ♀ (160 bytes) () 06/01/2012 postreply 18:57:42
• oh, i see. 這樣理解的確就講通了。 -tern2- ♀ (42 bytes) () 06/01/2012 postreply 19:28:10
• 現在老了。以前在中學時候對英文理解真是深透。 -youknowmyheart- ♀ (60 bytes) () 06/01/2012 postreply 22:59:29