Lindsay Lohan -- No Drugs or Booze for Me at Coachella

Lindsay Lohan is going on her yearly pilgrimage to a place where drugs and alcohol are as plentiful as Botox in Bev Hills ... but she SWEARS she'll stay clean.

Lindsay is telling friends ... she doesn't care about all the snipers who are scoffing at the recidivist rehabber -- she says she's not living her life for other people.

LiLo insists she's going for the music and wants to have some fun -- just like last year (above) -- before checking into the rehab facility for a 90-day stay.

Lindsay is also insisting she doesn't have a problem with drugs or alcohol ... leading lots of us to wonder how on earth rehab is going to work. In fact, Michael Lohan told us Thursday on TMZ Live ... he expects his daughter will fail.