Weight training is something I've been doing since I found my first Bench Press in the trash when I was in high school. I loved the feeling that I got after a tough workout, which in those days consisted of Bench Pressing most days of the week. Besides the rush you get after lifting weights, I loved it because it allowed me to release my aggression in a positive way without going to jail.
You can't bullshit the Barbell, the weight you Push, Pull, Squat, Dead Lift or Carry is that weight. You can't lie to the Barbell, you can't fake it when under a Barbell, the Barbell is the great equalizer. And by "Barbell" I mean any tool you choose to weight train with (Kettle Bells, Dumbbells, Barbells, Etc).
Weight training will bring out the real you very quickly, you will see if you're a Warrior or a Wimp immediately; that's the power the Barbell holds. Now I'm not talking about how much actual weight you load up, I'm talking about how much heart, how much desire to succeed, how much aggression, how much tenacity or how much love you have for yourself.
Weight training for me is necessary, I do it because I love it and I love how it makes me a better me. You shouldn't do it because you feel guilty about eating like shit, you shouldn't do it because you hate yourself, you shouldn't do it because someone tells you to, you should do it because it makes you a better you. It makes you better at your job, it will make you a better husband or wife, and it will make you a better human who will then spread their positivity to others.
The human mind and body desires challenges or we would simply atrophy and die. Stimulus is what keeps us adapting, growing and getting better. Challenging yourself often must be a daily part of your day if you want to tap into your full potential as a human being.
Why do you Weight Train??