This is a good text (FULL version) about important vital questions. It is laconic, substantiated and constructive (offering a step by step solution of a problem). It is very likely that this text is correct. Without it, it is difficult to guess how to act in life, and it is possible to fail through errors and even fatal ones. It is written with the life experiences of two people with, as it appears, not bad logic, of doctor and mathematician, well and, certainly, with their errors, for example, to spend all life for self-development only, excluding children – it’s “expensive”. It was initially written for own children and their families, to not repeat the same things to each one, i.e., this text is a reference book without art and marketing embellishments.