Much of the growth in Spain has been through EU grants totalling billions, invested in airports, roads, trains, banking, industry, arts and culture, healthcare and social programmes - and Spain is set to receive another €45 billion between now and the year 2020.
The amount Spain receives from the EU has been curtailed somewhat due to less well-off countries from the east joining the European Union, but the financial benefits Spain gets in return for its membership fee of 1.24% of its GDP remain very high.
José María Gil Robles describes the EU as the 'vitamin pill' that put Spain on the fast track to becoming a modern western country and the returns have been worth it for Europe, since most regions are becoming net contributors rather than net beneficiaries, with the exception of Andalucía, Extremadura and the Spanish-owned city-province of Melilla on the northern Moroccan coast, where the GDP is less than three-quarters of the average for Europe.
Even life expectancy has soared in Spain as a result of the EU's stimulation - from just 76.4 three decades ago. It is now one of the highest in the world at 83.2 years or over 85 for women.
Life-Changing Ideas, Hard Bargaining and Top Negotiating Skills
Although Spain signed the treaty to join the EU on June 12, 1985 - 31 years and 11 days before the Brexit vote - its membership was not complete until January 1, 1986.
Spain was, predictably, vociferous and rebellious as a member, but could never have been accused of not fighting its people's corner or pushing for change - tugs of war and heated debates going on until the small hours bore fruit all round and although Spain initially resisted some of the changes imposed on them - fearing they would destroy the country - many of these, such as the industrial reform, turned out for the best.
The then socialist president Felipe González said he was 'terrified' when he got the orders to 'either get rid of, or completely rehash' an industrial sector Brussels had told him was 'completely out of date', but admits that without it, Spain would not have the thriving motor export industry it does now, with Europe's largest Ford plant based just south of Valencia, in Almussafes, along with sizeable plants manufacturing other makes.
González says the fact Spain has more green-belt nature reserves under special protection orders than anywhere else on the continent is largely through the EU's iron fist - and funding.
Before the Berlin Wall came down, Spain was the country which took the most cash out of the EU for infrastructure and the second-most for agriculture.
Spain's own contribution to the EU has always been hugely valued - even if it has not always been in financial terms, the hope, strongly pro-Europe view, momentum, dedication and highly-qualified, hard-working civil servants were, from the beginning, what gained Spaniards the nickname of the 'Prussians of the South'. Also, Spain opened the Latin American trading market to the EU, thanks to its own cultural, historic and linguistic ties.
Everyone who benefits from EU citizenship, from being able to vote in European Parliamentary elections and the human rights charter, has Spain to thank, since it came up with the ideas and worked with France to push Germany into agreeing - and the so-called 'Spanish model for immigration' has been hailed as a blueprint, especially given the country's wildly cosmopolitan nature with over 140 nationalities living side by side in harmony.
One-time Commissioner Joaquín Almúnia cites all this, but admits that these days, Spain's contribution to Europe includes an 'unacceptably-high level of unemployment' and that politicians have become gradually more distant from the EU because Spain is 'too busy navel-gazing'.
The College of Europe alumnus Manuel Marín feels it is Spain who has lost its way in the EU rather than the other way around. Once the hard negotiators known for their bargaining prowess, they are now being likened to cash-stricken, debt-ridden Greece, which is disastrous Marín admits.
Spain is losing its interest and influence in EU
Once, Spain offered Europe the 'wisdom of an old nation' and the 'energy of a new nation', in the words of president Felipe González, but now, González himself feels Spain has lost its influence and is bringing nothing of real value to the EU.
Germany appears to be the main driver, but largely because not many countries want the job and, as a result, Spain and other EU nations are relying far too heavily on the Germans to come up with the solutions, the former PSOE leader reflects. "We need fresh dedication from nations who really believe in Europe to prevent the Euro-Sceptics and nationalists from eroding it and letting their inflated egos get in the way - and clearer leadership and greater democracy is necessary," González considers.
He says Spain's slow emergence from its financial crisis-years is inefficient and painful, socially, but that Europe as a whole needs solid security and foreign affairs procedures in place to solve the refugee situation as well as a drive to get back to the EU's one-time strategies that aimed to quash growing social and financial inequality among citizens caused by an increasingly-global economy and political panorama.
The general consensus in Spain is that Europe is 'part of the solution' rather than 'part of the problem' and that it is Spain's job as a member to contribute towards the changes it wants to see.
Whilst the Brexit vote has left the rest of the EU reeling and given a surge of self-confidence to the far right and Europhobes, there is a growing sense in Spain that if the UK genuinely does not feel part of Europe and does not believe in the unity and teamwork of its nations, it may be better all round if it did, in fact, break away.