^^^^ Yeah, absolutely go for it! Hopefully this sticky helps give MANY people a little push to get going if they are having second thoughts about whatever reason, not just age...

But 16 is still a great time to start and if you're still at it and going strong by 20, you could pretty damn good at it... If you want to put it in perspective, a guy just joined my gym who is 48 years old. He came in in a suit about 2 months ago to ask about prices and classes. He then drove off in his bmw, but has been back to 2 classes a week since. His first session you could tell he probably hadn't done much physical exercise in years. He could barely skip. When he could manage to co-ordinate for even a few seconds to jump the rope a few times, he was puffing and panting and had to stop after about 6 seconds. He could manage about 3 pushups in a row and not to many more situps/crunches.... Aside from knowing southpaw's put their right foot forward & that the jab was a dominant punch, he knew nothing else about stance or anything. Basically he was a 48 year old office worker who hasn't done much his in his life other than work in an office.
2 months on you'd think he'd been training for years. Not that his skills are years advanced. Not that his physical abilities are years advanced. Not even that he can skip for the full 3 rounds without having to stop 100 times. But that first day, he looked like he didn't belong anywhere near a gym and should have stuck to sitting in front of a computer. Now it's hard to picture this guy sitting at a desk.
He's improved about 1000% in everything he did on that first day. His commitment is 100% as if in a few years he COULD turn pro (I mean that as a figure of speach). This guy is now a boxer. Not an amazingly flashy/good or even average boxer... But before he stepped into the gym that first day, i'm sure you could call him nothing more than a pencil pusher...
When I think of the first day he came in, to ask for prices in his suit, and even the first day he came in to train and we thought we better set an ambulance on the quickdial incase the guy had a heart attack, and compare him to how I see him now, he's a totally different guy... And im sure he feels it too.
And you can bet your SwEET a** that that guy probably told himself a 1000 times that he's too old to start boxing before he finally took the plunge and came into the gym. You can probably gaurantee that if he told anyone around him he was going to start boxing they probably would have told him the same thing. But none the less he ignored it all, came to the gym, and i'm sure he'll never look back.... at 48 years old.. But let me tell you, in just 2 months he's dropped 10 years... Seriously....

So certainly, no one is too old to start boxing!