I have been recently thinking that it actually does make a lot of sense that I was happier in Finland. Then I lived 7km by bike in -10 to -30 degrees Celsius from anyone, so it was easy to say "sorry I will not make it I'm not feeling fit enough". There were not many activities going on anyway, at least there was no chance to do more than one thing per day, because of the above cold and bike. There were no public transport vehicles that would be delayed and make me feel guilty for not making it on time. There would be no people appearing upset at me - as there were not much people.
I thrive in the nature. My pain starts when human interactions start that need to be managed. During Erasmus I didn't have to manage much, the state of art was clear. Once I need to interact with people, negotiate my boundaries, manage my relationships in a wider context, or in a non-horizontal relation - that's when the problems with codependency start.