Well, a healthy dose of exaggeration never hurt anyone
But seriously, it's better to be safe than sorry. Every country has its own sources and systems for delivering water, so there's always a different balance of pathogens. If you live in the area, you've built an immunity to it. If not, you might end up with a nasty case of traveller's tummy. Mostly in eastern Europe, though. Generally drinking water is safe in the north and the west.
Same applies to dishes where unboilt water is used. I remember once being in Ireland for a week for a round-trip. Against my usual fashion, I ate a salad in one place. The next day, I was sick as a dog. Although it could have been just a bad salad...