Do you have kids/grandkids (if you're 25, pardon me for asking)? My grandfather, a lifelong smoker, died of a heart attack when he was 60 and my grandmother, who didn't smoke but breathed his secondhand all her married life, died of cancer at 57. I never met either one; my grandfather died a week before I was born. My mother has never quite forgiven him for that.
A college friend of mine had a really hard time with it, quitting and relapsing over and over, but he always commented that things smelled and tasted better, he got sick less, and didn't get as out-of-breath running around campus when he wasn't smoking.