this means your really efficient at utilizing DIETARY fat for energy. some people are not. some peoples bodies are way more prone to storing dietary fat, and then after its stored they use it as energy if needed.
some people are so prone to storing dietary fat , that if they had not eaten a single meal for months and were on the verge of starving to death, that if they ate a meal that only contained fat, their body would still store 90% of it first before tapping into it for energy.
you on the other hand sound to be efficient at utilizing dietary fat for energy. as well as carbs.
and again repeating myself here

the body can very easily burn both fat and carbs for energy at the same time. just cause your consuming carbs to fuel your workouts does not mean your not also going to burn body fat.
I'm sure you've noticed this about yourself
note: of course if your taking in more and more dietary carbs, fats, or total calories then your expending, your going to end up storing the extra (but that does not mean your always just going to get fat .. thats a misconception)