Crazy how different healthcare is in different countries.

In the UK once you've had your childhood vaccinations it's entirely possible you'd simply never see a doctor again in your life until you're ready for your prostate exam in older life.

There are no regular checkups or preventative care on the NHS for mid life adults unless you're proactive

I presume you're not a woman, because there's cervical screening for women aged 25-64 every five years. Also depends on what you mean by "mid life", but there's breast screening offered to women aged 50-70 and bowel cancer screening offered to people from 50 to 74 every two years.

There are real trade-offs with screening, and screening too much has harms as well as too little, although I'm not qualified to make a judgement on where that line sits relative to where it is in the UK.

To be fair, almost nobody is going from childhood vaccinations > late-middle age without seeing a doctor. And when you do go with an ailment general blood tests seem pretty standard these days at GP's along with standard vitals checks. They also do preventive care where necessary. Every woman is invited for cervical screening once they turn 25 and then every few years until they're in their 60's. Regular mammograms are also a thing after a certain age/depending on risk factors. Bowel cancer screening too. STI testing is free and, depending on where you live, done by post. Also depending on your definition of 'childhood' there are a few vaccines given when you're a teenager (HPV for example). And if you ever travel you'll be visiting the doctor for vaccines then too.