Moyamoya IS a progressive disease.
To the extent that your brain "found a way around it" (an appallingly ignorant statement coming from a physician, I might add), it may be that you have been able to compensate for it. My husband presented at age 58 with almost no symptoms. His neuro said that other arteries (external??) were compensating somewhat for the occusion and atrophy of both his internal carotids and that sometimes people who are of higher intellegence can compensate -- for a while.
I do not mean to be harsh, but it is also foolish that you have not seen your neurologist as directed. You need to have your disease monitored regularly, even if you are taking a "wait and see" approach (which is madness, as far as I'm concerned). The numbness you report are symptoms of TIAs (transient ischemic attacks) -- mini-strokes. Do not ignore these, because they can precede a major stroke, which can result in severe disability.
My husband came downstairs one day last fall and said "I seem to be having trouble pronouncing some words". My immediate thought was mini-stroke, but he refused to see a doctor. It went away and he thought no more about it until he collapsed in the bathroom on July 20 after a chemotherapy session (he also had bladder cancer) and hit his head on the wall. A CT scan revealed at least one "old infarct" (stroke).
He had EDAS bypass in August and was doing very well -- good response to his chemo and looking forward to his second EDAS and ending treatment and moving on with his life. But he did not follow instructions on hydration and aspirin and guzzled gallons of salt-riddled tomato juice. On September 21 he began slurring his words and his hands shook. He refused to call his neurosurgeon and refused to go to the ER. The next morning I woke up and found he had had a stroke. He was still conscious, but began having seizures even before the EMTs arrived. He went into status epilepticus and even though I had him transferred from our local hospital to the hospital in NYC where his neuro team was, it was too late. The local hospital had let him remain in status for too long and he never regained consciousness.
I struggle between grief and being furious with him for not being willing to follow simple instructions and seek attention when it was needed. Now, you are young and you do not have the complication of cancer to deal with. And not everyone with SE dies. Most of the time they can knock down the seizures with sedation. He was just unlucky and had bad care until I was able to get him to the experts. But you are ignoring instructions just the way he did...and you do so at your peril.
Please do not screw around with this any longer. Please make an appointment with your neuro. You need CT scan/MRI/MRA and perhaps a carotid angiogram. Please do not wait until you have a stroke to find out that moyamoya is progressive. Please promise me that. And either post an update here or send me a PM. I am not kidding. For the rest of my life I am going to be a tireless fighter against both bladder cancer AND moyamoya. I do not want anyone else to wake up and find their loved one sitting in their own feces, dazed and confused and unable to speak coherently.