So you'll be 27-28 when you get out, you'll likely have some money in your account and hopefully some skill you can then apply in the civilization workforce and it will get you out of your parents house. Not too bad of a deal.
The downsides: it won't be easy, at least at first. Your life as you know it will be over. You might get sent to some shithole of a country during some dickshit of a war. You're stuck for four years no matter what, there's no resets or saying "I don't like it"