re: Someone explain the BB ending.

It took me a while to come to grips with Jesse putting the pieces together after reading up on the the Brock poisoning incident.

Jesse suspected Walt because the cig went missing and accuses him of poisoning Brock. Walt was able to manipulate Jesse because of the missing cig. Jesse falls completely for it especially after Walt "dicovers" the missing cig in the vacuum thing. So Jesse's instincts are that Walt was the person behind all of it, but he allows himself to fall for Walt's trick.

Fast forward to this episode. Jesse suspects Walt of killing Mike, accuses Walt of killing him, accuses Walt of wanting to get rid of Jesse only for his own benefit. His instincts are right on again, but he allows himself to fall for Walt's tricks again because of a hug.

Jesse discovers how the weed and cig were lifted by Huel and realizes his instincts were right about Walt all along. He doesn't know how Brock was poisoned, but he now knows his initial suspicion were on point about Walt controlling that whole situation.