As Andres said, this can happen, but the numbers are vanishingly small. My Goddaughter was one of the genuine cases and it is a terrible thing to suffer from. Her teens were horrendous, anorexia, bulimia, breakdowns etc.. She still managed a 1st at Bath Uni, but a year late. Lots of late-night emails exchanged with me and others. She became a paramedic - won her area's 'paramedic of the year', wondered if she were bi-sexual or gay.
When she was 28, gender dysphoria was finally diagnosed and medication and surgery embarked upon. All going well, accepted by friends & family (now I had a Godson).
He was found dead almost exactly a year ago.
It's horribly hard for genuine cases and the avalanche of public 'fakes' and the abhorrence they engender has just made matters worse. I have no time for these people once they are adult, kids can get confused and be unsure.
Regarding the OP; the abolition of open changing rooms (which I avoid) and the reintroduction of cubicles could help a lot.