Yeah, me too, in theory. But then we get to the nitty-gritty of the thing, like, where's the capital and part of me goes "Not fucking Madrid, nope!"
Yeah, a lot of Portuguese history can almost be summed up as "Spain GTFO" - it's one thing to be on amicable terms, it's entirely another to remember that our only land border is with a country that's at least 3 times bigger and has its capital right in the middle of the whole peninsula that contains both countries - practically the definition of uncomfortable geography.
Then again, Spain barely seems to manage the regions it contains that already have their own languages and ambitions of independence, and that seems to translate into efforts to have most of their media dubbed in Spanish to try and enforce some sense of national cohesion, which hasn't done any favours to many a Spaniard's English skills in my experience...