I wonder how you could enforce a life time ban?
Passenger lists are kept for a very short time only for reasons of privacy and space.
If you were a frequent flyer there may be some information saved about you but I do not think there is any reliable way of tracing ad hoc passengers.
If insurance companies can keep tabs and flag up on bogus claims using some sort of software then I'm sure airlines can come up with something similar. I'm pretty sure if Jet2 banned someone for life then Monarch Thomson BA etc would also like to know the history and take appropriate action if necessary.