I've never gotten the flu shot and I've never had the flu.
This may be something senior citizens or those who take longer to recover from illness. Having said that the flu shot is generally a "guess" as to which strain is likely to be prevalent in a given year.
Sometimes they guess wrong and the strain that was given in the shot is worthless because that year we were hit with a different strain.
The shot is neither good or bad but whether effective or ineffective.