If you want to practice patience and the horror of letting go, cacti are there for you.
You'll soon learn that sometimes what the subject of your care needs the most out of you is nothing.
Overdoing is a death sentence; overwatering, over sunning, over shadowing. The damned green nub might even seem to mock your ministrations when you're not looking.
Let it be, please. Remember the name Münchhausen.
The desire to act is the most insidious poison for a cactus; it will get you high off the delusion of the importance of your actions as it drowns your plant, which will fuel further your thirst for action and the inevitable death-spiral of rot and fungi.
It doesn't need salvation. It certainly doesn't care for it.
All it asks for is a little water, enough sun, some repotting and, of course, love. Always love; just not enough of the stuff for it to kill the cactus.