My housemate learned on a manual transmission and then drove an automatic after that. His experience was that being required to manage the gearbox meant his mind was more fully engaged with the act of driving - when he was driving the automatic, he found he was paying less attention to the road and his driving became worse.

I enjoy driving, and using the manual gearbox very quickly became automatic anyway. Occasionally I'll change gear and change my mind about which gear to go into halfway through, then accidentally put it into 2nd gear at 40mph. This alarms the passengers. And in a typical long-distance journey I'll attempt to shift into 6th gear every thirty minutes or so before remembering halfway through that my car only has 5 gears! I'll always prefer manual transmission for two reasons: a) the folklore is that manual transmissions are more reliable and easier to fix and b) anyone I teach to drive in my car will get a full license, not an automatic-only license.

There was a cartoon I've been meaning to draw for years now. It shows the difference between European and American cars. European cars are basically a giant shoe or rollerskate, like a kind of clothing that you strap onto yourself that enables you to move around at 70mph. American cars are like a mobile living room where you sit and wait for your destination to appear around you!