When I searched for the causes of common cold, I found out that it's only cause is the spreading of virus and that it's a myth that you get cold when you get wet. If that is true then how does the virus start to spread if no one else is having cold? Or Simply, Can you get cold by yourself without the virus?
No, only virus or bacteria can cause you cold .Cold weather causes increase in the spread of virus. Flu virus spread quickly in cold weather. Cold feet can slow down your immune system making you prone for virus attack.Means ,if you are wet you are susceptible to a viral infection but the cause of cold then would be a virus not the cold weather itself.
Influenza isn't the same virus as the common cold.
Rhinovirus ("nose" virus) is the main cause of the common cold. This is a virus that exists in the nasal passages of all humans. It replicates, like all viruses, by piggy-backing off the metabolism of the host cells (yours). It's present in us, a normal part of the microbiome, but harmless most of the time -- it gets ahead when you are immune compromised, exposed to temperature challenges or chemical challenges, or are infected with some other microbe.
The virus reproduces by making your cells build virus proteins, copy the virus genome, and then build the virus particles that are released to infect more cells. The ideal temperature that human Rhinovirus proteins fold up and work best is slightly below human body temperature. This limits the virus to the cooler part of your respiratory passage -- your nose.
When you are exposed to cooling -- being caught in the rain for example -- your nose and upper respiratory are cooled. This results in the virus replicating at an accelerated rate.
The new viruses leaving the host cells they were made in and invading into nearby cells causes an irritation. Your body tries to dislodge this irritant -- you make excess mucus and you the urge to sneeze
Sniffing or snorting will introduce this mass of viruses deeper into your respiratory tract. They aren't able to replicate here because of the temperature being too high, but they can irritate and invade into your cells. Your body detects this challenge and responds with inflammation, swelling, and as a side effect, pain. Your sore throat.
Ironically, the activity of the immune system responding to this actually harmless virus will compromise the tissues of your throat, and any opportunistic pathogen is more able to invade.
https://en.wikipedia.org/wiki/Rhinovirus this the wiki of the rhinovirus