"One hitter Quitter" real or myth?

[beachguy in thongs]

Tetrahydrocannabinol (THC)
Chemical name (-)-(6aR,10aR)-6,6,9-trimethyl-
3-pentyl-6a,7,8,10a-tetrahydro-
6H-benzo[c]chromen-1-ol
Chemical formula C21H30O2
Molecular mass 314.46 g/mol
Boiling point 200 °C
Solubility 2.8 g/l (water, 23 °C)
CAS number 1972-08-3

What's that mean? 2.8 g/l (water, 23 degrees celsius)?

One hit would be a lung/throat/mouth/nose filling hit, OR one pinch.