For those who may have trouble with loops, take heart: after 45 years of non-stop programming, often 10+ hours a day, I still find myself sometimes doing mental

For those who may have trouble with loops, take heart: after 45 years of non-stop programming, often 10+ hours a day, I still find myself sometimes doing mental loop simulations with small (few element) data to make sure a loop is correct. It's usually much easier to take extra time to make sure it's right than to debug it later.