My DD is 4 1/2 months, and apart from a few bumps in the road she's generally an easy baby.
Everyone prepared me for the lack of sleep...it's all anyone said to me when I was pregnant 'you'll never sleep again' (as it happens she's a good sleeper so far).
Nothing prepared me for the constant worry you have as a parent and how that means you literally can never switch off, somedays I go to bed with headache from just overthinking everything all day long and that itself is exhausting. Just the fact you are 100% responsible for this little human 24/7. It's often overwhelming but I hope with time that will get easier. Someone tell me it does? lol.
Then I see other people with multiple kids, still going out drinking, weekends away, holidays with just their partners kids left at grandparents etc...and I'm like it MUST get easier or they are just better at switching off and being more carefree than me.
I do miss my old life and the old me and for the first 10 weeks I think I couldn't accept how much of a change my DD was to my life, I sort of rebelled against it and that made everything seem awful, but once I accepted life is now different and better, parenting became easier. That's not to say I wouldn't love a night just being me again at some point instead of just mummy.
Life was easier without kids but the grass is always greener, and before I had her or was pregnant, I used to look at other mums in the supermarket or garden centre and think to myself, one day I can't wait to have that. And now I do, so I try count my blessings no matter how up and down the parenting journey is!