I did a year in UK and another 5 months in Paris. Biggest barrier was getting everything sorted at the start to replicate my organised life in US/Canada. I was proficient in French which was a bonus and cos i was at University had a lot of support from an welfare officer in each case to ensure it was settled. Took a bit of time to learn new routes and shopping was harder as nothing was the same brand but mostly it was like moving cities in the US.

I lived in the UK for a year, visited Italy, Germany, and Norway for a couple of weeks each. Italy was rough - traffic is nuts and the narrow streets wind around, often without sidewalks and the people were kind of grabby, pulling and directing me instead of asking if I needed assistance. Germany was great! The only thing I would caution there is that you will have to be the one to ask for help if you need it, they don't approach you to offer help. But if you have your paperwork in order and enough savings to start a life there I think it would be a great thing to do! I really enjoyed my time there.