Close languages often seem weird to each other. ;) It's because you have an unavoidable bias - when hearing/seeing Czech, it almost seems like it's your own language, yet somehow everything is wrong, twisted, shuffled, shifted, etc. When you look at a distant language, you take it more as it is, not as a strange version of your own language.
When I see or hear Polish, it's like being in continuous amazement: Why? How? Why? What? WHY? Why do they say it like that? Why on Earth would they use this funny syntax, pronunciation, archaic vocabulary, medieval spelling, weird and intense melody, all those loanwords, so many sibilants, stress on the wrong syllable, and so on and so on :D It just doesn't happen with any other language like that, by far.
Thanks AgnusOinas; For Polish people Czech always sounds funny (really very funny), but I was told by my Czech son-in-law that Polish sounds funny to him, and to you as well, I presume.
I have very similar reactions to Czech as you describe above, it amazes me all the time and then I get frustrated when something is not the way I figured. But then a lot of things look obvious by analogy. I think for English speakers it must be really hard, I appreciate their determination. I read somewhere, probably in DL forum, that Polish is the most difficult language (for English speakers), I wonder where on the scale they would put Czech.