A then and now picture book with text, cleverly and humorously puts across the salient differences between modern living and cave man days, as only Munro Leaf can do it. And at the root of the differences lies SCIENCE. The cave boy is Ugh; the modern boy is Younow. Ugh had to depend on catching animals for food; a super market makes it easy for Younow, and a stove and refrigerator come in handy. Ugh had skins for clothes, while Younow has clothes made of any number of things. A cave may sound romantic but it isn't as comfortable as a house. And then there are differences in transportation and communication; why in Ugh's time they grunted and growled. School helps make these things possible, and holidays offer a variety of good times. And by sharing all this with others we all have better lives.