I agree with write everything down. I 'interviewed' my Auntie for my research into our family tree, and wrote down everything, including all her little anecdotes. One of her tales was about an old Irish lady who used to call my Grandma Mrs Duffy when that wasn't her married name at all. It turns out (after much research by myself) that my Great Grandfather was into identity theft and his real name was Duffy, but if it hadn't been for this tale from my Auntie I might never have found out. It was just that something in my research came up with the name Duffy, and I might have dismissed this little clue if I hadn't heard the tale!