Training day after day on a flat surface such as the mats of your dojo, can leave you with some bad habits. The chance that you will be attacked on a smooth flat surface is next to zero. So when your instincts kick in you will be probably be learning for the first time what it is like to defend yourself on an uneven surface.

In the dojo, you can get away with dragging your feet, and can count on consistent grip on the floor. In the dojo, you don't have to contend with kerbs, fallen chairs, table corners etc. Although a safe training environment is important when running a class, it also leads to a lowered sense of awareness.

I recommend conducting some classes outdoors. Taking ukemi on grass can be quite a different experience, and at the same time greatly increase your confidence. Try to perform a technique on an incline and you will immediately notice the extra effort required to cover distance uphill. Wet grass can result in a sudden loss of traction, or a tree root can trip you up.

If the above occurred in a combat situation, would you maintain your composure and focus? Would you be able to regain your balance?

I find kumi-tachi (paired sword training) perfect for outdoor training. It requires you to cover more distance, at greater speed, and deal with avoiding a weapon. It is also a great opportunity to utilise the additional space if you have a smaller dojo or the ceilings are low.