I have two children and I feel absolutely horrible admitting this but I’m doing so to try and address it. I feel so differently towards them.
I have a boy who is 3, and I’ve always found him difficult. I don’t actually think that he is, it’s me. I had a horrible birth with him and was put on a feeding plan that looking back was just insane and got barely any sleep for the first month, so I can put some behaviour down to lack of sleep but I was so so angry all the time. This lasted for ages, I was spitting with rage for so long 
Things got better when his sleep improved but he was approaching toddlerhood by then and his behaviour was challenging me and I still find this such a struggle not to be filled with rage.
I have a baby as well and my feelings are just so different.
I worry so much I’m going to do irreversible damage to them both. I really do try not to show angry feelings and it isn’t like this all of the time, there are good times, but I just don’t like how different it feels. So for example, I couldn’t wait to get back to work after DS, with the baby I am already feeling like I’ll need therapy. I loved it if anyone ever took DS to give me a break (not that it ever happened mind) but with the baby I hate it. I’m so much more patient and kind with the baby even if only ‘in my head’ 