I wish to place on record my respect for all those fellow members who have shown such admirable patience in taking the time to reiterate the very basics of commercial air travel ; the sort of basics (law of supply & demand, no divine right to any specific seat number, upgrade availability changes by the minute (let alone by the hour/day) .......etc etc....) which really shouldn't need explaining to anyone who has flown anywhere near as much as the OP claims to have done.
And ....... a special mention to eternaltransit. Your detailed response (post #11) is above & beyond the call of duty ^