If you red Devil Dodo wrote then thisw ould explain Yoda sensed fear in Anikan when he was a boy and they inorged his feeling and his fear and lack of patience. Luke Anikans son was like him but how could Yoda be sure so he Yoda: (irritated) I cannot teach him. The boy has no patience.
Yoda: Much anger in him. Like his father.
Yoda: Ready? What know you of ready? For eight hundred years
have I trained Jedi. My own counsel will I keep on who is to be
trained! A Jedi must have the deepest commitment, the most serious
mind. (to the invisible Ben, indicating Luke) This one a long time
have I watched. All his life as he looked away to the future, to the horizons. Never his mind on where he was. Hmm? What he was
doing. Hmph. Adventure. Heh! Excitement. Heh! A Jedi craves not these things. (turning to Luke) You are reckless!
Yoda: He is too old. Yes, too old to begin the training.
Yoda was trying to judge by his reactions like his dad he got angery when he didn't become Jedi Master so Yoda tried to drive Lukes will determination and his anger but at the end of the discussion he showed no anger so he gave in and decided to train him and in this quot Yoda: (sighs) Will he finished what he begins? Luke I won't fail you -- I'm not afraid. Yoda: (turns slowly toward him) Oh, you will be. You will be.
and if he fears the dark side he won't join then. 😄