Is this normal? Latin-based language question?

Yes, they are similar... take it from a Romance language native. I'm Romanian and by viewing some tv shows in Spanish I am fluent in it(not joking) I staid two months in Italy and I'm fluent in that too. Spanish and Portuguese are very similar even though you might not think so at first(they are pronounced differently). Careful with Romanian though, it's the most difficult out of the big Romance languages. If you know vulgar Latin it is easier cause it's closer to Latin than the others.