Well, the attitude thing is the thought that you're hampering your own growth by thinking that you'll turn into the Hulk overnight if you work too hard. Short of insane doses and decades of long work with brilliant genetics, there is no way in hell you could get to Ronnie's mass.
Most of us (both naturals AND big juicers) have been sacrificing and eating and sacrificing and bleeding for years on end, sometimes decades, with the sole goal of getting bigger and we're not even close to that kind of mass.
Not that most of us want to be superheavy pros, but we know the sacrifice required to reach 'master of iron' status. Decades of work man. It's almost kind of insulting to think you can just get 'hyoooge' with a couple pin pricks and a few months. Louie Simmons has a bottle of test in his office and has been on a cycle for 28 straight years and most of us would not call him hulking. Not that I recommend that kind of AAS use mind you.
Just pointing out that the kind of ' I don't wanna get too big' attitude is self limiting and self-defeating, and insulting to others who understand the kind of pain and blood it takes to really get there. The people who think that way are the same people I surpassed a few years ago, and are STILL not making any progress because they don't want to work hard and bleed 'cuz they'll get too big.
If it were that easy, then just about every 135lb newb who lifted for a year or so would look like Arnold. And guys like me (also not a bodybuilder) who've put in 7-15 years of solid work would make Ronnie cry.
Now, I know you didn't mean it that way at all, but that's kind of how it comes off sometimes, and whether you realize it consciously or not, that is the underlying thought process you have right now. Sometimes Freud is right :). So, this is not a personal attack, it's just me explaining why you got jumped on a bit. It's a bit of a pet peeve for a lot of us.
It's really frustrating to hear that kind of phrase come from others in real life and on the internet in countless posts (while asking for us to help them), so sometimes we jump the gun after hearing it for the 100000000th time.
btw, I'm 6'1" and now at 230, and I feel like I have plenty of athletic ability. I was never really "fleet of foot" but I can still tightrope walk and rock climb. If I were to climb a lot more I'd probably bring my weight down about 20 lb or so, but you are definitely on the skinny side. Don't be afraid of putting on slabs of muscle--as long as you train athletically, you'll only improve with more muscle.