why sometimes I watch polish tv and I can understand almost everything,
What are some samples of things you understand almost entirely vs only understand some things?
It might be related to time.... sound in movies from the 1990s tends to be worse as it became fashionable to mumble....
I find older movies (up to late 1980s and then sometime after 2005 or so) to be easier to understand than those in the middle.....
The differences don't make much difference to native speakers but can make things much harder for non-natives.