Men, have you ever wondered why your spunk looses it's spunk as you get older?! (Did you see what I did there?) Urologist Harry Fisch explains,

As a man gets older, the prostate gets bigger and the semen volume, the fluid amount.. decreases. And because the prostate gets bigger, believe it or not, it blocks the small ducts - the ejaculatory ducts, they're called - where the semen comes out. The ejaculatory ducts are the little tubes that course throughout the prostate into the urine tube called the urethra...

The writer cuts off the urologist mid thought, so we never get to know why the prostate gets bigger, but it makes sense. It's basically like stepping on a hose. The older you get the bigger your prostate gets and it causes pressure on the ejaculatory ducts and then less pressure builds. The less pressure builds, the less jizz comes out and the weaker the shoot. My friend noted, "So that's why some guys are shooters and some guys are dribblers." Indeed!