I talk to the Spanish about things like WW2 (mostly they know very little about it) I suspect the Portuguese are very similar. For example they know nothing about Britain being blockaded and having to modernise their agriculture or starve. Or having to buy tractors etc from the Yanks and then pay for them for years and years (unlike some European countries that got loads of aid). Britain even paid for rebuilding Belgium and in return got cabbages (which we apparently tipped into the Horth Sea rather than seem ungrateful as we had plenty).
Large numbers of the other countries in the EU either were uninvolved and therefore probably disinterested or under Soviet rule and anything is now better than that.
I would wager by the same token that not many countries know or understand the pain that the Spanish went through with their very recent civil war. Guernica? Sadly this is all part of the modern world.
On a more individual note we had the dubious pleasure of a 38 year old drop by traveller. He claimed to be an invalided out of the German SAS and was trying to canoe 250 miles along the rivers and reservoirs to reach the sea, sleeping rough each night. He had capsized and punctured his canoa(which turned out to be not much more than a kids inflatable raft )and most of his possessions were wet. We did the decent thing and let him have a shower, washed his clothes and fed him well. Among the topics we discussed were the EU. His view was that we were all just a drain on Germany. When he proudly said his Dad was a Nazi, I was so glad to see the back of him when I dropped him off 50 miles away from our house to help him on his way.
I repeat that what the British need is factual info on the EU (good and bad), benefits and drawbacks. I can't see us getting that anymore than their being an in out referendum.