I think for me it is an age thing. Plus access to the internet!
I definitely worried less with DS1. I just got on with it I suppose? I didn't know any different, didn't have groups to share ideas on, very little in the way of socialising, no friends well not with babies at 17! and no baby groups to go to. It was all gut instinct. Apart from being a whinger, he was easy in other aspects such as sleeping and feeding. It is funny how since I have had O, my memory about DS1's baby years has seriously faded! 
I did not worry one iota at putting him with a childminder at 6 months. I didn't worry about how I fed him. I didn't worry about any of it.
This time. Worry fucking worry worry worry! Arghhhh!
I've got it all the wrong way round!
I suppose I am actually more relaxed though, as I did worry what people would think about me, with being young. I always made sure we were both immaculately turned out, clean etc. To the point I was buying new buggies every 3 months when they got a bit dirty or scratched. Shoes, I was obsessive with not letting them get dirty. No dirty face, covered everything when eating so mess didn't get on stuff. I was quite strict with him really, in terms of behaviour. Not a good place to be in, but done with the best of intentions.
I could be like that this time, except, I no longer give a shiny shit what people think of me! The benefit of age I guess!