I’m not too familiar with the Southern European languages, but I am quite familiar with the Northern European languages. That is where I find the opposite of your difficulty happen, where all those languages look like a different flavour of German to me, so they were very easy to pick up, because I could just read Swedish slowly without ever looking at a textbook or dictionary, and over time I found myself quickly able to write it.

Differences between people, or differences between cultures perhaps. Having grown up in the Netherlands I did already come across Frisian and Limburgs, which are also slightly different but if you keep reading or listening you just pick it up. So I don’t know, keep practicing I’m sure you’ll get Spanish!