Self defense is a lot more than physical techniques.

Self defense requires a passive awareness, or situational awareness. I'm not suggesting a paranoid state, but just being aware of surroundings, where the exits are, an alertness to situations or people that are out of place.

There have been debates on going for quite some time regarding the efficacy of sport Jiu Jitsu vs the Gracie self defense curriculum. Most Jiu Jitsu athletes in general have decent stamina, endurance, and the athletic ability to defend themselves. The sport teaches adapting to changing circumstances, physical techniques, and there is a "toughness" byproduct of the training. 

The self defense curriculum teaches these things, but it also teaches a philosophical element to defuse, redirect, or to avoid violence if possible. Another point regarding self defense would be, its best to end the situation quickly and if possible avoid going to the ground, especially against multiple assailants, or in unfamiliar surroundings.

The two come from the same roots. There are many places the two intersect. Gracie Jiu Jitsu consists of five elements: standing surprise self defense, striking, throwing or clinching, grappling, and philosophy.

I like training with no clock/timer, you can't be saved by the bell. You need to use different strategies. Sport is fast. You have limited time to work. While from a superior position this may be advantageous, from the inferior position against a heavier, more athletic opponent from a self defense standpoint you may waste energy, exhausting yourself trying to make something happen, when patience, waiting for the opportunity would have paid dividends. To attack the average person leaves a lot of openings to exploit. The strategies are different but they tend to reap similar results.

Just some of my thoughts.