Could I live without the Internet for a month? Sure, I've done it before. Would it drive me nuts? Sure! Of course, without the Internet I'd probably be unemployed. That's not a happy thought.
For personal use, though, I could do it. The only real problem is that throughout the day I get some odd ideas, like "Can you cook with cottage cheese?" or "Why does the microwave superheat my bowl, but leave the contents stone cold?" Stuff like that. Without the Internet I'd have to do something like go to a library, which I wouldn't do because I would forget it eventually. Or I might wonder who starred in "Barbarian Queen" and not be able to check.
Believe it or not, I lived during a time when there was no Internet! None at all! At least, not for public consumption. But I did have a bucket load of BBS' to call and waste time on.