Very early this year. There are two different jabs. One for the over 65 with antibodies for 3 strains and another for the under 65s with antibodies for 4 different strains of flu.
Last year I had a sore swollen arm and a bit of a temperature for the best part of a week, but this year only one day afterwards. Worth putting up with for not getting a bad bout of flu.
However, I cannot complain about a "lucky" bout of flu in my early 30s. Once I might have felt like a cigarette again a week later, I had effectively gone through withdrawal and never wanted to smoke after that.