[Event] Ask the Experts: Navigating Retirement Taxes

Very last question if you don't mind....

"(The "Forever Rule"): The earliest funding event—whether it was a $5,000 contribution 10 years ago, or a $1 conversion 5 years ago—starts the clock for all your Roth IRAs. It is a one-time, lifetime clock for the owner."

I have only one Roth IRA.  In this Roth IRA, I have mix of after-tax contributions I made starting 20 years ago and Roth conversions I started this year.  Does "Forever Rule" mean earnings 5-year clock started 20 years ago when I made my very first contribution for all my after-tax contributions, both the contributions made 20 and 15 years ago?  

Much appreciated!!