I have once meditated on the Maha Mangala Sutta and I slipped into deep concentration. I opened my eyes and felt my carotid pulsating and I didn't even have to touch it. It felt like it was throbbing and it didn't go away for the rest of the evening. Also, since then, every time pirith is playing, and I choose to listen in, it is always that particular sutra. When I am not even listening to the words of the pirith, I always know that that one sutra is playing and I decide to listen in on the words. What could be a reason why I am experiencing this?