I get the impression that English's lack of signifying prefixes/suffixes regarding gender or people, for example, is part of my difficulty learning other languages with seemingly more complex grammar. Kudos.

Well, to be fair Polish (and many other languages) has/have both byzantine grammar and forms that are alien to English speakers. This article is weird to read as Pole, but I can kinda dig it at least in terms of "why could that be so complex" explanation.

Edit/arseshelter: just to make sure we are on the same page, I don't think of Polish as the hardest language or agree with quite a few things in article itself regarding difficulty assessment. It's largely OK as presentation of one point on it being hard, but I do recognize how people learn in different ways and speeds. To me, Spanish is too hard and makes so many weird rules about pronunciation that even German and French seem almost sensible (and I remind you, one has umlauts and another seems to need each vowel in at least two or three flavors). Portuguese? No, thank you. I want at least one consonant that sounds like I know it ;). The point is: article shows some difficulties and should not be considered as authoritative. Or that I wanted to present it as such.

Ah, yes. This always is fascinating to me. To learn a language to a point that your brain (or you) can encode and interpret information in a form other than your native or preferred medium.

I don't think that's that. Let me try this one:

Back/return, Here/there, is/are, It, Me, Go, Good/bad, Where, Stop, For, If/else, While, I, You, There, Just, Get, Up/Down, Left/Right, Not/No and counting to about ten is enough to be very expressive. You should know enough programming to know how much you can do with just that :P.

That's why knowing just a few gestures + hand alphabet allows deaf people to communicate so quickly. You probably need a solid understanding of as little as about 50-80 words to convey the core meaning nine times out of ten. "This not nice, it look bad", but you don't need some fabled Fifth Conditional (the preposterous case, describes a negative probability of occurrence) or 20$ adjectives to get to the core of information.

It's not hard to reason on a "Simple English" level of Wikipedia. I think on a Simple Swedish and Simple Czech level, only add some more stuff from time to time. With time, it could actually become something around fluency, but unlikely to ever get better than my English. Which on the other hand sucks compared to my Polish.