It was then Lance knew…he was fucked, literally and figuratively. 

So Blue is actually pretty unique compared to the other lions, he’s actually quite curious and wants to learn about humans. He finds them fascinating, especially their wide array of emotions and beliefs. As he learns more he actually wants to be like them, which baffles the other lions immensely. 

Even though the lions have an array of emotions and personality quirks, they’re still machines, and when things get down to the wire, they will go back to programming or their mission so to speak.

But Blue wants to be more than that, wants to have another purpose besides Voltron, and he sees that he could accomplish this with Lance.