Out of all these it's quite simple to dismiss the psychological explanations of LC. There are obvious physical changes found in various tissue and blood in LC patients. Changes that we can be reasonably certain aren't caused by mental issues.
Then it took me more then half a year to get back to that point. It was a very slow recovery but most importantly, it could be quantitatively measured first from how far until I had to disembark my bike to walk up the rest of the hill to eventually the lowest gear I had to to shift into to get to the top without ever disembarking.
I’ve never had any other flu-like sickness cause me to be weak for so long.
One should remember that the flu has been around forever, so the flus you are comparing to were probably the 10th exposure - recovering from a new illness - and not being a small child - may take much longer.