Possible Clues:

• 'I remember when ...'
• Lead-in to a nostalgic observation
• It raised a catcall, as in the past
• 'Back in the day ...'
• "Used to be ... "
• Nostalgist's opening words
• "In the good old days ..."
• Reminiscer’s intro
• 'I remember when ...'
• 'I remember when...'