Differences among English speakers

Hi!
These days I´m realizing how different the accents are from people who speak the same language! Let me give you an example(for instance and example have the same meanings), to me, (a rookie English learner) it´s Mission Impossible to understand Scottish accents (I´m not criticising Scottish people, obviously it´s my fault) nevertheless I understand (reasonably well) people who speak English but who are not from the United Kingdom, such the Polish, Croatians, Italians(you are talking about the people, so use the plural form), etc.
It´s fun to hear different accents from all over the world, I guess that the same will occur with people who are trying to learn Spanish, even to me, (a native Spaniard) it sometimes is difficult to understand people from Andalucia (and Andalucians will say the same about people from Gallegos!).

I'm awaiting your corrections!
Many thanks!
Bye!