When it comes to training in the self-defense arts you play the way you practice!
Let me explain.
Imagine practicing baseball but with an imaginary ball. Every grounder, line drive, fly ball, short hop would be a perfect play. Why? Because the ball is imaginary. You're not practicing with live variables. But if you go into the game and throw a real ball in, what's going to happen? Disaster! You're not capable of reading the ball off of the bat, the ground or in the sky. You don't have the skills to manage those plays because you did not practice the way you play - with a ball.
TIP - practice your self-defense the way it will actually happen. You should practice outside in all conditions of weather - yes this includes cold, rain, snow etc. Why? Because it's real. The likelihood of being attacked in perfect circumstances is a dream. Furthermore, you should practice in real clothes and shoes - not a martial arts uniform. Clothing can restrict your movement. Heavy coats and gloves can hamper your techniques. Practice this way so that when an attack does happen, you are prepared, confident and know what to expect. Remember perfect practice, makes perfect!