Essentially you're asking someone to potentially share medical/work information. I'm not really sure how one person sharing their individual circumstances is going to help you understand the differences in the rollout.You're right its none of my business, but if you dont ask.....and I'm not forcing an answer.
As for the differences in roll out, actually I dont know all the reasons maybe an answer to my question would have informed me of one of them.
In the end I think asking someone who is being open enougth to say in a single post that they are getting a booster very early in the program and then shortly after going on a 10k race how they are in that position is fairly reasonable
FWIW differences are likely due to different demographics in different areas, different levels of vaccine availability in different areas, how the rollout of the first two jabs went, how on it different GPs/health authorities have been. That kind of thing.