I don't own Monk. This is inspired by the chapter in Bob Wright's The Twelve Numbers Of Monkmas when Monk explained his past behavior to Sharona

"Okay," Sharona said calmly, "Adrian we both know I'm not going to listen to you when you talk like that. I'm a human being with feelings that matter. I don't appreciate the way that you've been talking to me just a few minutes ago and I have no intention of listening to that nonsense. It's not my style and it's not my personality. Furthermore this is unconventional behavior for you so why don't you just tell me what's going on… what's REALLY going on"

Adrian hesitated but he knew she was right. Sharona wouldn't listen to him when he was being stupid… or as far as she knew stupid. She didn't know of the danger she was in.

"Okay," he said, "the truth is you're in danger"

That got her attention.

"You have one minute to explain what you mean," she said

"We got this," Adrian explained and pulled a note from his pocket.

The note was simple. It read SHARONA F IS AS GOOD AS D E A D AND G O N E"

"That's why you can't go anywhere," he explained, "You're my best friend and I can't lose you too"

Now she understood why he was behaving the way he was. He was simply looking for the first opportunity to protect her and he found it. He put a limit on it for two reasons. The first was that he was sure he would catch the person with a couple of days and if he didn't he could just extend it… finding some reason to do so. In the second place he didn't want to upset her any more then she had to be.

Sharona was his best friend. She pulled him through his funk more then anyone. He knew that she wouldn't understand it.

"Don't worry," he assured her, "I'm not gonna let anything happen to you. You mean too much to me"

She blinked.

"I do," she asked

"Of course you do," Monk said, "You're wrong when you said I don't care about you. I care very deeply about you. I will not lose another person that I love even if that means that you're mad"

Sharona shook her head.

"Wait, back up. You love me?"

"Not like that," he said, "I can't love anyone like that anymore. But yes I do love you"

Sharona stayed put for 20 days until they caught the SON OF A BITCH that sent that note. Who was it? Well… in an ironic twist of fate it turned out that the one who did this was none other then Judge Brandon Rickover.