In the first paragraph of Wuthering Heights, Lockwood strongly approves of Mr. Heathcliff, his new landlord. He says, "Mr. Heathcliff and I are such a suitable pair," and then, in a burst of enthusiasm, calls Mr. Heathcliff "a capital fellow!" (We might say, "a great guy!") Lockwood goes on to state in the same paragraph, "my heart warmed towards him...".
Yet in the second half of this opening paragraph, Emily Bronte already has begun to cast doubt on Lockwood's judgment. The reader might well question what a great guy Heathcliff is when Lockwood describes his suspicious eyes and the way he draws his fingers even further into the vest he is wearing as if recoiling when Lockwood speaks to him. Heathcliff's body language is closed off and hostile. Further, the words "suspiciously" and "jealous" which Lockwood applies to Heathcliff might make us wonder why Lockwood "warmed" to him.
Part of Bronte's genius is her ability to very quickly get a scene going. She does so here, and from the start we recognize Mr. Lockwood as an unreliable narrator, forcing his own interpretation --what he wants to believe--on to situations even when the evidence contradicts him.