understanding foreign languages

I'm going on two trips this year, one to Spain and one to Scotland and I've realized something about these trips.  I don't speak Spanish at all so I have no expectations of understanding people there except through translators or the hope that they speak English as a second language (which, I've happily discovered, many people in other countries do and I admire them for it). But somehow I feel that I ought to be able to understand the people of Scotland. After all they do speak English, sort of. I remember a conversation I had with a local the only other time  I've been in Scotland.  He was giving me directions and it was just lucky that he pointed while he talked because I couldn't understand a word he said.  I am doing my homework though.  I've gotten hooked on a Net Flix series called "Monarch of the Glen", a fun soap opera in hour long episodes that takes place in the Scottish Highlands.  The scenery is fabulous, the characters are interesting, and, depending on how thick the accents are, I can generally understand at least most of what is being said.  I love this homework.