you know why John says there were 153 fish (21:11), don't you? It's because there was one more fish than 152, and one less than 154.
I've been thinking a lot lately about little seemingly unimportant phrases. I know I include them all the time. When telling a story, later on I might look back at how I told it and wonder why I included a detail that wasn't important and maybe bored my listeners. Mostly it's just because I'm a disorganized thinker.
But the Bible was inspired by the Holy Spirit. So what's up with the recent 3 year lectionary texts where Mark says the disciples took Jesus in the boat "just as He was" (Mark 4:36)? How else would they take Him? Or why mention the woman had had the flow of blood for 12 years (Mark 5:25)? Why is the amount of years important enough to spend ink on?
One explanation I've heard about the 153 fish is that such a specific number testifies to an eyewitness account. That's good enough for me.