Why does Double Clutching work

First of all it makes the driving experiance more fun

Second, it simply gets the gears in the trans all moving the same speed so you hardly need the sycros to help the engagement.

 

I learned bothe double clutching and rpm shifting in a 48 international with
A 5 speed tranny, 3speed brownie and a 2 speed rearend, all manual shift..3 shifters.
Since then I've never ground a gear.