Because technically there is no such thing as cold
all that exists is heat
this is because heat is the rapid movement of particles, made by friction (to understand why you must delve into physics and some chemistry)
so, when you feel cold, it's really the absence of heat
so instead of "keeping the cold out", which makes no sense at all scientifically, insulation keeps the heat in.
as a side note
the feeling of cold is produced when you come in contact with an object (yes, air counts) that has less heat, or energy, than you do, You feel cold because heat (energy) from your body is being transferred to the environment. This ABSENCE OF HEAT in your body is why you feel cold
Explanation:
because the full movie called the amount of each other and can help you to like let's say 11 in it to keep on counting the distances you won't be keeping record of it so that you will know that you did you did a great