Last, but not least.
This proverb means that the last item or person mentioned should not be forgotten or overlooked, as it is equally important as the previous ones.
A possible/common pattern to arrange a speech or essay suggests putting your strongest and thus most important argument favoring your own opinion first and conclude with the weakest, thus least important argument.
When you watch the news, it normally starts with the biggest headlines and then ends with "and finally...", which is usually something like someone's pet hamster learning to dance. When you write a to-do list, you normally remember to write the most important/stressful things first, and then when you go further down the list you add less important stuff as you remember it. I think it is natural to have important things at the forefront of your memory so that you don't forget them.
It would be embarrassing if you were mentioned last because the speaker had forgotten you until the end, but this is a way of saying "I didn't forget this person/thing, it is simply the final item on the list."
