You know, I thought I’d lost him – Voldemort – I thought I’d lost him – and then my scar started hurting again and I had dreams of him and I could even speak Parseltongue again and I started to feel like I’d not changed at all – that he’d never let me go –

And had he?

The part of me that was Voldemort died a long time ago, but it wasn’t enough to be physically rid of him – I had to be mentally rid of him. And that – is a lot to learn for a forty-year-old man.

Harry Potter and the Cursed Child - Chapter 4 :
See this quote in the Pensive -