I didn't bother till my mid 30's. I live in a city...so private vehicles are restricted and public transport is almost always going to be cheaper and faster. I only learned in the end as I kinda fancied the novelty, it's considered essential to advance in my career and I suspected the criteria was only going to get tougher.
There are things that crop up where you simply need a private vehicle though...my mum went into a somewhat rural hospital long term...public transport is a 5 hour round trip but maybe 70 mins by car, no contest and I wouldn't have been able to rely on the goodwill of other drivers forever. A number of my friends who recently had kids are finding it near essential as well, they need to carry around so much stuff that public transport isn't a good option (unless you're on of those prats that tries to squeeze down a train carriage with like 5 backpacks on)