1. When armies would clash and a river or lake was in the way, they would simply walk down to the bottom of the lake/river (ignoring any scientific laws of the density of the human body) and walk up the other side of the lake/river rather than swim across.
2. The soldier did not get to pick and choose which army he was a part of. Either God put him through a random placement generator, thus placing him on the according army, or if his family happened to have the same coat-of-arms as another individual, he would be grouped with him, whether or not any connections between the two existed.
3. The medieval world must have had relatively few artists because of the great lack in the amount of coats-of-arms.
4. Soldiers were not allowed to swing at any angle. Each was forced to swing in only 4 different directions.
5. Annoying punks we find nowadays MUST be descendants from Horse Crossbowmen.
6. One was completely capable of carrying a polearm or two handed weapon that lacked a scabbard on their back by simply shoving it through the chinks in their armor, and were also very capable of being able to pull it out in a very timely fashion.
7. When a soldier was carrying a secondary weapon and wished to switch to it from the weapon he then possessed, there was no such proccess called "sheathing your weapon". The scabbard/belt of the individual had a magnetic mechanism that pulled the weapon he was then carrying into the respected place, giving the time it would originally take to put your weapon back in place to grab his secondary weapon.
8. Every 30 seconds in a battle, a soldier, whether he were living or in the arms of death, would find a bag of gold on the ground with varying amounts (this depended on how well his army was performing) within. Along with that, he would also have a moment of enlightenment that made him/her more of an experienced fighter (this 'enlightenment' came along with the finding of the bag-o-gold).
9. There was no such word as 'endurance' or 'catching-your-breath'; medieval knights and soldiers could run freely, no matter the weight of what they were carrying or wearing, and as long as their hearts desired. This rule applied to horses as well; they did not require the need to be fed/watered/rested.
10. Sticking hundreds of pounds of armor on top of your horse, as well as adding the weight of the plate armor you wore on top of it, did not dull its performance.
11. Peasant soldiers could easily take a spike/blade/knob the head or face, and still perform perfectly fine in battle. You then come to the conclusion that this was the result of grueling work on the farm under the burning sun.
12. Some 'two-handed' weapons were easily used on horseback as a 'one-handed' weapon.
13. Hordes of soldier, with verying cultures and backgrounds, often invaded a village in waves in order to take possession of a young woman (who is presumably the only resident of the village).
14. If a soldier was lacking a shield and happened to spot one in the heat of battle, he/she was able to pick it up as well as paint their coat-of-arms on the shield in a very neat and artistic manner within the matter of milliseconds.
16. When someone was placing a helmet upon their head, the individuals head would lose every strand of hair, becoming bald, in order to place the helmet on.
17. Beards must have been quite strong; they were able to go through the chainmail one wore upon his head.
18. The defenders of a castle would usually break a chunk out of the wall in order to let the besiegers place their siege equipment against it.