From Zhou to Han dynasty, Tai Sui was observed. People took into consideration whenever there was 'Dong Tu', building and even in marriages.
The "Wood Star" which is called "Sui Xing" was the reference for Tai Sui. Tai Sui is observed based on a calendar year which is the exact opposite travel path of "Wood Star". It is also referred as the "Lord of All Shas"
Each year, Tai Sui is observed in order not to offend through disturbing or confronting in a renovation. Once offended, it will be inauspicious or even spell disaster.
有犯太岁之人必定要小心过年。如运呆滞, 又重犯/冲/刑,雪上加霜。
San Sha (三煞) has been observed by many people. It is a year directional sha. Eg, in year 2008, 坐煞 is 巳,午, 未。夹煞 is 丙,丁 mountain. Disturbance in the form of renovation in the South will 犯煞。Resulting in loss of wealth, health and tragedies. Accordingly, it has to be faced rather sitting on it.
Does it matter to everyone? Or does it matter at all?
Another term for five yellow 五黄 is 廉贞 阳土。This common term five yellow once activated will cause problems in work and frequent sickness and accidents. More serious due to combinations from the year and months may even results in death.
The above is base on various conditions met.
In terms of Shas, there are many others like 二黑,破军,岁破, 小儿杀,different forms of space and form shas. All the above are actually an imbalance of the earth and atmosphere.
All can be easily dealt with if one understands the nature and source of such shas and applying the different methods to neutralise.
In fact, its not an issue at all when one understands metaphysics.