Most men wouldn't trade even a quarter-inch of penis length for ANYTHING.  Money?  World peace?  A delicious sandwich?  Not worth it.  Not even the sandwich.  Which is why THIS will mess with your head.

--Here are three things that will make your manhood shrink . . . PERMANENTLY!

#1.)  Smoking.  Smoking damages your blood vessels, which can make less blood flow down below . . . so when you get engorged, it's SMALLER than it could be.

#2.)  Erectile dysfunction.  This adds insult to injury for guys with ED.  Without regular erections, your tissue down below becomes less elastic.  And that can knock off almost a FULL INCH of size over time.

#3.)  Getting older.  By the time you're in your 60s, you start losing length AND delicious girth.  You can drop half an inch to an inch by the time you're 60, and even more after that.

(Jezebel / WebMD)