This wasn't exactly a question Neville was prepared to be asked, let alone by a girl. To be fair, Neville could've dreamt about walking a pet crup and still felt shy about sharing it, especially with Parvati, who would certainly tell Lavender, who would certainly tell Seamus, who...
"I was... at home with Gran," he began reluctantly, looking down at his own parchment. "And she kept insisting that I had put my shoes on the wrong feet but when I looked down I wasn't even wearing shoes and there were, ah, these fish? Swimming around? My feet, I mean."
Neville should have been well past being embarrassed. As it turned out, he had a singular gift for feeling so.