vipassana progress questions Does a stream winner who practices vipassana tend to have a feeling being oblivious to most of things he thought was very important before.It's a feeling as if things don't really be marked in the mind as very important as it used to be. Is it possible to happen?
It's possible but not necessarily a sign of having entered the stream. If someone engages is vipassana meditation for a couple of decades f.i. there can also be an increased lack of interest in things or forgetfulness. Just due to increased habituation of new ways and natural wear-and-tear of old habits which are no longer supported.

To be on the safe side: I would suggest to see it as a sign progress and of effective meditation rather than as a sign of being a stream-enterer.