Congratulations on your first lucid!

I think the "WILD while sleeping in your dream" was something similar to a DEILD... You probably fell asleep in your dream (Which normally causes you to walk up) and instead of waking up transitioned to the next dream..
Or at least something similiar to this.. if you saw the HH and had the SP you normally have in a WILD...

If it wasn't that, it might of just been a change of scenery by closing your eye...

Either way you had your first.. So