My boyfriend, who is 22 and from Oklahoma, has had a learners permit since he was 16 or 17. He was even allowed to renew it as a learners permit when he turned 21. They've still not made him get an actual license. He went to OU which is small enough that you can ride your bike around town, he homeschooled himself for high school so no need for a car there, and he's in his second year of law school in DC. Other than an inordinate amount of teasing from me about having *renewed* his learners permit, he's not had any issues with it.