Why is the US so big?

I am from spain and I just can't make the terms of how big is USA because all the states are so big, are they really too big to see it? I just have been to Texas and Florida once but I don't feel how big it is because I didn't go to other states, I live in Barcelona and the next town is 50kms away but you can see some of the other towns from it, with a big town like Madrid I need to drive another 6 hours and is still too close, but everything has its own cities and towns and not too far from each other, what i mean is that to go from one town to another is not a journey, it's a day to day drive, to go to see my family it's a 6 hour drive and is like in the other side of spain it's not a big country, even if i go to other countries in the EU, like Germany or France, is not a journey it's just a drive, but people sometimes say is too far because you have to fly so the flight is only 3 hours, but then you need to go to the airport and to go to the airport will take you another 3-4 hours, so it's already 6-7 hours, but i think going abroad is not a big deal, is just i take the car and go easy, but i always just go to places on one day car drive, but 6 hours don't feel too big just too far like, why in other countries is just another town, why in the US Texas and Florida is like Germany and France? I can't get it right, all the maps are not really good, they have to be too small to show all the cities and towns, i can't really feel how big it is because how much towns are in a single area, just to go to the next town is 100 miles of driving, i just can't understand it.