I just made a great discovery on WILD.

This is what happened:
I came home from church. I was a little tired so I decided to try and WILD.
So I went to my bed, took a comfty posture and tried to relax. I relaxed more and more, and I started to go numb. I got frustrated so I rolled over to my back. I kept my eyes closed and I started hitting my palm in frustration. I did that for about 2-3mins(weird) and then I just stopped. I wasn´t trying to WILD, nor thinking of just falling asleep. I just laid there. Then I started having the "BEEEEP" sensation that I get before SP. I also started hearing some sounds.

So in a nutshell:
I relaxed and tried to WILD, which gave no results. After rolling over and doing lots of physical movement, and then just stopping I started getting SP in prolly a minute.

This confuses me. Why did I get SP sensations after I stopped WILDing, and after I had done a great deal of movement? And could I use this to WILD?