This franchise is HUGE and VERY episodic so it varies between entries, but more often than not he's consistently shown to be pretty impulsive and spontaneous, and he can and will spend days hyperocused on planning and pulling off heists, and a lot of the time it's purely on a whim. He's not out to get rich or help people in need; he only does what he does because it's thrilling and fun and keeps him from being bored. Plus, he tends to do a lot of vocal stimming, especially in his youth.