A big job ahead

Why do we keep abusing our bodies and treating them like crap?  Sure a lot fo the time it's enjoyable, tasty, easier, etc BUT we only get the one, so why do I find it so hard to treat myself well by eating and exercising properly?  We have become such a lazy society and I am ashamed that I am part of that.  Ofcourse I wasn't always, before I hurt my back I was cycling ~300km's+ a week!  I need to get back there but it's tough, it's far from easy and it's also frustrating, but I really need to so it, I was really happy with that lifestyle and while my current lifestyle is easier, it's no where near as enjoyable.