Why is it advised (here at Outdoors) to tie a bowline knot with its ending on the inside ("Standard Bowline") and not at the outside ("Cowboy Bowline")? See pictures below.
If you're unlucky the end can get stuck, and you can't untie it.
Scenario: Tie a boat with a bowline knot around a pole. The end can get stuck between the line and the pole. With the wind pulling, forget the trip or cut it.
Also, I use different knots, but this is an official knot for tying a boat.
I couldn't find a pic with a pole and have no camera, but imagine a pole in the loop (of the inside bowline) to the left of the end. Then the end can be in between the loop and pole. Then imagine a tremendous amount of weight pulling the line.
Figure: Left is a standard Bowline; right is a Cowboy Bowline (source: wikimedia.org):