do joints work after the first few tokes?

[AandS]

the lit end of a joint burns at a minimum 400c it is 10mm wide and 10mm deep.
thc vaporises at 200c.
i take the first deep breath on a new joint,the thc in the first 30mm of the joint vaporises(because the tip burns at 400 while thc vaps at 200) and i inhale,then i pass the dutchie to my friend.
he inhales and smells+tastes the marijuana which i also smell+taste.
the thc hits me but does it hit him as much?.i say no because if thc vaporises at 200 surely the first toke is the strongest(taste and potentancy )
SO does a joint work at 50% strength after the first toke?or have i just been smoking to much;-)

holy hell man
you're thinking about it wayyyy too much, just smoke it

to add, wouldn't it make more sense if the joint would be more potent once its almost finished, cause of all the previous smoke with thc in it passing through it?

just a thought