met_em and wrfout not matching

[WRF_user]

Hi,

Can anybody help regarding the following questions?

Is it true that the values for a variable (at fixed location on the grid) from wrfout* files should be equal to that in the driving data in met_em* file?
If they are not- (i) could you provide little hint? (ii) what about the first model forecast hour? e.g., I have simulation that start at 00 hour and the wrfout's will be produced every hour, should I expect the wrfout's 00 hour having the same values as my input met_em's? I did not get them quite matching, for example for Soil moisture using NAM data.

*wrfout = wrf history files

Thank you.