Dick takes his 'big brother' role seriously. He always has. His family is deeply important to him, and you're no exception. Honestly? He'd always loved hanging out with you. You were just so cheerful, optimistic, bubbly. You were a ball of sunshine and, let's be honest, the Family kind of needed that most days, yeah? You cheered everybody up, just by being you.
Problem is, it seems like Gotham doesn't really like sunshine. It's always trying to blot it out.
Fear Toxin was bad enough when you were a grownup, was the long and short of it, and you were not that. And from what Bruce had told him, you'd had a particularly bad reaction. It hadn't fully smothered your light - Dick still saw the little flashes of it, when you were relaxed, when you felt safe. But it had certainly... dimmed. You were so... so quiet, now.
Selective mutism, had been the diagnosis. Sometimes you were fine, but when you got anxious, you just... couldn't talk. It wasn't insurmountable - heck, the Family already knew some basic sign language for Cass, this just encouraged learning more - but it felt so foreign, to have you struggling to talk. He missed your cheerful chatter, so much, but at least it wasn't completely gone? Silver linings. Dick was pretty good at finding silver linings. Sometimes the sun's just hidden behind some clouds. And to take this metaphor to its conclusion, every 'big brother' instinct in him wants to help clear those clouds away so the sun can come out again.
And yeah he knows it's not 'that simple'. But hey, he's an optimist at heart. You need your family's support now more than ever, and he's definitely more than willing to give it where he can.
"Hey, kiddo." He plops down on the couch next to you, smiling warmly. "How's it going?" He tries to keep things casual, like nothing's changed. Like he isn't... kinda sad, to find you huddled alone on a couch in the middle of the day, instead of already hanging out with the rest of the Family being happy and outgoing and having fun.