In all honesty, L was more afraid of being forgotten than dying. If he died now, he'd be remembered, until the few people he had actually met died. And then what? Nothing. Just an old record of him solving some hard cases. Nothing special. Nothing to set him apart. He had not written anything important, and so he would not be remembered like Shakespeare is, even though there are only five facts known about Shakespeare's personal life.
Needless to say, L tried to ignore his fears. But every once in a while, the malevolent voice in his head would whisper, Mess up, Lawl-i-et. You're never going to do anything worthwhile, Lawl-i-et. And then the fear would come in, making him want to curl up in a little ball and stop thinking for five minutes. But the thing with L was that he never could stop thinking, was always analyzing something, even if all he was doing was eating cake. His brain was constantly processing information - texture, color, flavor, sweetness, flaws, et cetera. It was frustrating.
Having Matsuda around did help keep the negative thoughts away though. Or, at least, not affect him as much. Matsuda was so optimistic that it was impossible to be pessimistic around him, really. But if Matsuda's notions were completely out there, L would speak up. Matsuda might get a swelled head if he didn't, and who needed that?
Of course, dating Matsuda was completely different from just having him around. Because whenever L felt those thoughts creep in, he would just kiss Matsuda. And while it did embarrass him, L could tell Matsuda liked them. The spontaneous kisses might seem to Matsuda like L showing how much he really loved him, but in reality it was for a purely selfish reason - L didn't want to think, therefore, he kissed.
Matsuda!logic had nothing on L!logic.
