No offense, but this is the only way I understand your comment too, and apparently we are several people like this. If we take your two statements example, we understood your comment as if you were saying something like "if you are fit enough to run a 100 mile ultra marathon, you can run a mile in less than 5 minutes". Or "if you are fit enough to run a mile in less than 5 minutes, you can run a 100 mile ultra marathon", I don't know. Which might not be what you meant to say, but that's what we understood and why we are surprised.
No matter the logical mistakes people are doing while reading your comment, that's not what is important. What is important is understanding each other, and we apparently didn't get your point. You could rephrase it so we can understand what you want to say. You are telling us that we are wrong in our interpretation of your logical statement but that won't help us understand it. We are not trolling you or in bad faith.