Holden's memories of his childhood friend Jane Gallagher certainly have a huge impact on his life. It's obvious that Holden had a huge crush on her, which, sadly for him, was not reciprocated. Holden's unrequited love for Jane is a key formative experience, greatly influencing—one might also say distorting—his relations with girls.
Holden's selective memories of Jane are as a sweet, innocent girl, all sugar and spice. So when Holden finds out that she's dating the notorious womanizer Stradlater, he's utterly shocked and devastated. All of a sudden, that pure, unblemished memory of Jane he's been carrying around in his mind ever since he first met her has been shattered forever.
Nevertheless, Holden still retains an interest in her—an unhealthily obsessive interest, you'd have to say. Because of this obsession for Jane, Holden's unable to develop any kind of close relationship with another girl. He's still stuck in the past, still fixated by his childhood memories of Jane.