After the second world war Europe was broke (in more ways than one) - financially as well as infrastructure (roads, rail, cities etc.).
Even in the 1950s most of Europe was still poor (we had rationing in the UK into the 1950s).
But then gradually during the 60s, 70s and 80s and 90s things improved (even though the UK had its dips in the 70s) and gradually things looked rosy and the EU spent (wasted) money as fast as they could get it.
But then I think we (Europe) began to think the good times were here to stay for ever.
We began to borrow and spend money as though there was no tomorrow (individualy as well as countries and the EU), and we got very "generous", allowing immigrants and asylum seekers to come here and stay, often giving them homes and benefits when they had not contributed to the system.
Rather like a rich "lord" who has inherited his fathers estate and fortune and begins to spend it recklessly, soon you realise the cupboard is bare.
We (Europe) have been far too sily with our money in the last few years, watching our manufacturing business go to the Far East, China etc, but still continuing to spend as though people all over the world were buying whatever we made.
Europe is a mess, and countries like Spain, Greece, Italy, Portugal may never get out of their financial mess. Even we, the UK, are not far behind.
I dont see it geting better for years.