When a 60 yr old man sits alone he appears his full age.
when 2 office friends, 60 yrs old come together, then they appear only 30/30.
when 3 college friends, 60 yrs old meet together, then they appear only 20/20/20.
when 6 school friends, 60yrs old join together, then they appear as school children.
this is the mathematics of friendship!