Good question, which is addressed directly on my website:
I am teaching right now, so progress on the website is sporadic. However, I hope to get this site completed with illustrations that make it crystal clear what I am saying.
For now, the bottom line is this:
1) most cold viruses are RNA viruses (not super stable)
2) most cold viruses are small (10,000 bases of coding information)
3) most cold viruses have two speeds of replication (fast and faster)
As a result, most viruses are what I call "stupid viruses" and your immune system does its job easily and clears the virus from your body.
1) HSV is a DNA virus....just like the genes you carry from birth to death.....pretty darned stable stuff...DNA maintains its chemical structure even at 500 degrees farenheit
2) HSV has 150,000 bases of coding information.....that gives the virus a lot more tools (genes) to screw with your infected cells and your immune cells
3) HSV can alternate between two extremes of replication rate (fast and OFF). When OFF, no proteins are made and there is no way for your immune cells to figure out which cells are infected. Your immune cells see foreign proteins......no proteins ...no immune clearance.
In the news, we always hear about "viruses" like they are all the same. This is simply a lack of good information. If the smallest viruses like poliovirus were, say, the size of a perch, then the biggest viruses like herpesviruses would be the size of a Great White Shark.
Sure, they are both just "fish", but personally I am lot more scared of 20 foot sharks than perch. The confusion over herpes simplex virus is simply because the description of the virus is either way too simple or way too technical. It isn't that complicated, it's just not explained well anywhere.
Keep asking good questions!