Mentoring my first junior dev and somehow more nervous than I was as the junior

Got asked to informally mentor someone who joined last month, and I did not expect to feel this anxious about it. When I was the junior, not knowing things felt fine, that was the whole point of being junior. Now if I don't have a clean answer to their question I feel like I'm exposing that I've been faking it this whole time too. Anyone else get worse imposter syndrome the moment you're on the other side of it?