No, Its a wrong belief in common public. Saturn is the planet of Justice. So sometime he punishes for our past bad Karmas and sometime he relaxes us and gives compensation of our past good Karmas.
Moon is the only planet who is directly concerned with the verdict of Saturn, the Judge. Moon is mind so all the joy and sorrow are experienced by Moon only.
Sun is our Soul whereas Moon is our Mind , our Astral Body. Both are directly connected with our existence, our life, our experiences . Other planets are just the distributors of our past life karmas.
Understanding Sade Sati
Saturn is the last planet so he can watch our all activities during the life journey and gives the reward or punishment in the next birth when Saturn remains very close to the Moon and interrogate him during 7 and half year. This is called SadaSati.
If the Moon is exalted or vargottami and placed in Kendra or Trikona that means your past karmas are good and Saturn will give you Justice and free you from some long pending worries with compensation.
If you are born with Taurus or Libra Lagna Saturn will behave friendly with you and give some favorable results in SadaSati. If Gemini or Virgo Lagna then Saturn will not be so friendly but at least he will give Justice with soft corner. For Capricorn and Aquarius he will be neutral. For all other Lagnas he will see you like criminals.
Also please see the position of Saturn in the natal chart. If he is exalted or vargottami or in own sign he will always be in good mood like a Good and kind hearted Judge.
One thing more I have noticed that Saturn being the ruler of 8 number he punishes or gives benefit through 8 number only.
One gentleman of Cancer Lagna purchased a flat number 44 when he entered SadaSati and he lost 2 Cr in business after shifting to that flat.
A young man with Libra Lagna and vargottami Saturn purchased a car whose number total was 8. He got a good job in multinational company with handsome package. This all happened in SadaSati. He told me that when he joined the company was 8 September. This can not be just coincidence. There must be some secret link.
In short Saturn’s SadaSati is not always bad but it is just ‘HIS’ Interrogation with Moon who represents ‘YOU’.