How do we get temporary hearing loss from festivals/headphones?

Not everyone is a festival or concert kind of person, but after this summer, I have found that I definitely am. After listening to the Wallows on the first day of Reading, I experienced temporary hearing loss, as did all my friends while we were walking away from the stage. Everything sounded muffled, and I also appeared to be shouting at a very high volume just to be heard by my friends and just to hear my own voice, while at the same time, receiving weird looks from people walking around me. 

How do we get temporary hearing loss from festivals/headphones?

Why Do We Only Dream Subconsciously at Certain Times?

Have you ever been in an extremely deep sleep, the softness of your mattress feeling as comfy as a cloud while the most random, incomprehensible dream fills your mind uncontrollably? But next thing you know, it’s a few days later and you’re forcing a dream about an event that occurred during the day – it no longer being a subconscious one. Well, I’m sure you have experienced this at least a few times in your life because I most certainly have. But the question that made me the most curious was: ‘why do we only dream subconsciously at certain times?’. This question popped up in my head, funnily enough, during my attempt at sleeping during the sweltering, hot UK weather. Because it seems odd that one night you’ll have such a mixed, unfathomable and sometimes quite abnormal dream and the next night your mind is blank, and no dreams fill your brain but instead are filled with forced thoughts.
So, enough contemplating and questioning, and now time for answering.

Why Do We Only Dream Subconsciously at Certain Times?