"Gender identity is like a light switch. When you are presenting as the gender congruent with how you feel, your light switch is on. When you're presenting as a gender that doesn't match who you are, the light switch is off and everything becomes dark.
Most people are born with the light switch on, and never know any better. However for us, the light switch is turned off. Many of us try to find the light switch, and unfortunately many of us stumble, and even fail. But many of us succeed, and when we do switch it on for the first time, it's a feeling that only a few of us in this vast world are privileged to receive."
This was just an analogy I happen to think up while I was in the shower earlier. Thoughts are welcome.