Statistics - Intercept - Regression (coefficient|constant) <math>B_0</math>
1 - About
The regression constants didn't make any sense in a lot of example because it doesn't make any sense to get zero for all others predictors (others variables not regression coefficients). It gives a meaningless regression constant <math>B_0</math>.
In contrast, if X=0 and Z=0 becomes the average then the regression coefficient <math>B_0</math> is going to be the predicted score on Y for an average score on all others predictors. That's a meaningful value.