There's a PaulG tweet about this that I'll have to dig up sometime about how parenthood changes you and yes it will change you.
The first six-months to a year you won't have decent sleep. You'll learn how to function.
Really I think the difference is that you don't have much time anymore for distraction, you don't tolerate it. You can't tolerate it. Sure, you'll still be able to browse HackerNews and play games (sometimes). But those long periods of drifting off, spacing out, taking hours to finish something...you'll learn to stop that.
You'll become more efficient. You'll have to: the baby is hungry or needs to be picked up from daycare. Dishes need washing, diapers need changing. Some young dev is dawdling on about something in their day? No. Where's the MR, here's what you need to fix. Get it done. Push it out. We don't have time for this sh*t.
It gets real. In a good sense. In the best sense.
I think you'll wish you did this years ago.