Ronald Reagan's last joke -- Feb 1994 #ronaldreagan

I found this from February 6, 1994, Ronald Reagan's 83rd birthday.
This is allegedly his last official public appearance. Nine months later it was announced that he had alzheimers.

Anyone notice the obvious here? Reagan who on the date of this recording is roughly 16 months older than Biden, seems just fine getting through this 24 minute speech. He starts a bit out of breath and then seemed okay for an 83 year old man.