I really don’t know what the heck is happening anymore. I’m so confused rn

When they Tried the Expariment I am guessing The father Became Younger and lost all his memories uptill the point of his age so He dosent remember anything until that day of his life...Thats why he is also acting Childish and dosent remeber his daughter or his (not yet son-in-law) or that his I am guessing Crush? is dead