Because you have a shared energetic vibration with your Twin Flame that originates from the Source of your shared soul.
Your conscience keeps merging with yours as you keep downloading your energy into each other’s systems.
This is why when Twin Flames are together, you are always reading each other’s thoughts that you could say the same words at the same time, you can easily guess how the other is feeling with talking, and you do the same things at the same time. You could text each other randomly at the same time, you can also choose a fashion style that complements the other.
You are your Twin Flame in essence.