Because Sagittarius essentially spends all of their time in their own heads, they are all too familiar with the landscape of mental fortitude.
They are good at processing information, and they have a variety of coping techniques for dealing with stress or other problems in life.
Aries is one of the strongest signs intellectually since they have a history of getting themselves into sticky situations and finding ways to survive.
Leo is capable. Simply ask Leo. This isn't a joke, to be honest. Consider the job finished if Leo puts his or her mind to it. Leo has extraordinary mental fortitude and their prowess will endure the test of time.
To be that sadistic, you really have to have a strong mind. Furthermore, Scorpios are the true sadists of the zodiac. It's merely a fact that they genuinely take pleasure in your suffering.
Even though they aren't always the top "go-to" option for mental health, they still stand a strong chance of taking home the prize thanks to their mental fortitude. Health? Nah. Strength? Yah.
Cancers struggle with being stereotyped as the helpless homebody who always laments their sad fate.
They have therefore refined their "mentals" into one grand declaration of mind power in order to counter the effect of the rest of the world simply presuming they are feeble basket cases.