My dad was army since I was born till last year, always lived at gone that I remember. Of course you would spend a fair bit of time away when deployed or on exercise etc.
As for being selfish, I don't think so. It's your life, your future, your decision. Ultimately if it's what would make you happy go for it. It can be a strain on the family but certainly not selfish I don't think.
After caring for you for around 20 years spending endless amount of time and money on you? Yes, I probably would consider that selfish. my opinion - others may differ.
It's a catch-22. Could be seen as selfish in the way TZ says - could be seen as the most selfless thing to do with the sacrifices you'll make and the ultimate sacrifice you could make for the millions of people who will never even know you existed...
The other thing is your young and can enjoy yourself, do you want to be at home? Getting out and experiencing something new is something that you shouldn't under value.
No different to going to uni imo, that's a few years away and going home just from time to time. Follow what you want to do, it can be hard at home but in the end if it's what you really want, would you be happy doing something else
I joined when I was 17, after 6 months basic, went to Hong Kong for two years, I loved it! Fantastic time! In Germany as a singly, I did 3 tours in 3 years! I loved it! The only time the tours and training became a burden was when I got married and had kids. you only get 1 life, make sure you live it!
I think your parents issues stem more from concern for your safety. Years ago (likely when most of the above stories were current - correct me if I'm wrong) there was a far lower chance of getting shot at if you joined up (NI tours not withstanding of course). With the current world situation there's a far higher chance of a tour in an actual warzone.
Also - you say you want a career in the army but you want to live at home. Seems rather contrary to me.
No, I don't want to live at home (not that I dont like it but when I can. I'd like to move) but (excuse my sources) in quite a few films and documentaries I've seen the troops have been living at home (even if they're older than about 24/25)
james your best going down to your local careers office, and just ask as many questions as you want. The one i go to is really friendly, going back in 4 months to start my officer application. They are there to help mate, ring first and then go along for a chat and ask any questions you have!
As for being selfish, I don't think so. It's your life, your future, your decision. Ultimately if it's what would make you happy go for it. It can be a strain on the family but certainly not selfish I don't think.