The four specific areas that we want to mobilize in the Olympic lifts are:
Ankle
Hip
Thoracic spine
Shoulder external rotation
A lifter that doesn't spend time mobilizing these areas could have problems executing the lifts with any semblance of good technique. A lack of mobility in these areas can lead to compensatory patterns that could cause injury.
Why are people listening to fat guys who squat 800 pounds but can barely move? The truth is, running (not jogging) has a host of benefits to the weight lifter.