I bought my first copy of the Tao in 1986 and tried to absorb it. I was also a second degree black belt in a traditional art. At the time, I did not understand all of what Lee was trying to get across, but I did understand enough of it to encourage me to dig deeper and seek out explanations for what I couldn't comprehend. Reality is the truth. With this in mind, your mission becomes one of seeking reality in combat.
Reality is a perception.
What you perceive to be reality may not be exactly what your neighbour perceives to be reality. Lee took this into account when he said that your truth is not my truth and my truth is not your truth. We are all unique in how we perceive the world around us, and this includes combat or self-defense. Bruce Lee said that one person's reality in combat may not be another person's reality. For example, wing chun kung fu, which Lee learned from Yip Man, was an expression of what worked for the art's founder.