Maybe you're both right? Staying on the example of recitals. When I concentrate hard listening to the music they seem like they last forever while also being over in the blink of an eye!
Similar sensation to being in an isolation chamber
I think this is correct. Time is not, metaphorically, just the perception of elapsed seconds. There is a dimension of depth. And while it may “fly by” it can feel slow if it was spent with depth.
An hour on social media and time laughing with friends can both be fleeting but one will feel better spent.
Similar sensation to being in an isolation chamber