Hi Allison,
Welcome to the Dho!
Sounds like this experience that you had, whatever it was, still is with you at some level. Looking back on the time that passed since then, have you noticed any changes in yourself? in your practice? in the way that you relate to the world?
As for the experience, you say:
Allison A.:
Reality seemed to 'break', like glass, but then... continuously (if that makes any sense). It was beautiful, soft and unbearable at the same time, relentless. I noticed it swallowed everything: the music from my mp3-player, thoughts of not making my connection on the station, things forward in time, back in time, other people in the tram. It lasted for about... ten minutes (is what I now recall).
This reminds me of experiences of deep equanimity, of seeing the Suchness (also called Thusness or tathata in pali) of things. The layer of Perception (labels, comparisons, ideas about things, etc.) becomes less prominent and the experience is more immediate, more clear, direct, more real and somehow not quite real at the same time (all this is from my own experience, of course).
Allison A.:
It did not, though, feel like a big deal at all. It felt a bit like stumbling upon a nice flower, be surprised, smell it, and then walk on again.
Yep, it's a great way to appreciate the world. It comes, it's there and then it's gone, just like everything else. There may be some appreciation of the experience, some lasting joy in the heart for a little bit after that, feeling that one is "lucky" to have experienced that and that's it.
Allison A.:
It reminded me of the crispness of some haikus, and I have the idea there's references to this somewhere, probably in Zen literature, but maybe also somewhere else. I looked around, but I haven't been able to find it.
Yep, it's been described many many times but not in so many words. You may have noticed that words are not quite adequate to describe the experience.
Hope this helps,
Eran.