Order of lines can be very crucial... but most of the time it isn't.
Example of a crucial time:
Setting a variable at the END of a script
The variable MAY be changed in some other script
Checking the variable at the beginning of your script for any changes.
Of course, if you set the variable at the beginning and checked at the end.... it wouldn't do much, so having each line where it needs to be is very crucial in this case.
The one and only,
Those who live in the past, are destined to insanity. Those who live only for the future, will be slaves to their ambitions.
Those who live in the moment... only they, are truly happy.