TMZ knows exactly why Britney lost custody — she ignored the Commissioner at every turn.

Rewind to last month. L.A. County Commissioner Scott Gordon ordered Spears to do a number of things in order to maintain 50/50 custody.

Spears was ordered to meet with a drug counselor — she didn’t do it.

Spears was ordered to submit to drug testing — she didn’t do it.

Spears was ordered to enroll in parenting classes — didn’t do it.

Spears was also required to sign the judge’s order — again, she didn’t.

And last Friday, Commissioner Gordon prohibited both Spears and K-Fed from driving the children unless they had a valid California driver’s license. Gordon was pissed today when TMZ posted video of Spears cavalierly driving her kids around Malibu.

Source