I would like to understand why I got stuck with the middle seat, was it that I booked to late or should I have done something else.
Seats are reserved when most folks buy their tickets. That's why.
There have even been quite a few times when I've purchased tickets 7+ days in advance and the only seats available are middles or EMLs.
If you want to assure yourself a window or aisle, book on JetBlue.com and do so at least 3+ weeks ahead of time.