It's actually a bit sad that many of us can't have the same courage in our adult years that we did in our childhood. I think we probably try to chalk it up to "knowing better", but there is likely a bit of fear involved that we used to scoff at.
We're not born with a fear of failure but acquire it. Parents and school teachers drum it into kids. "Colour inside the lines," and, "do it like this not like that," are common phrases that contribute. People are taught to conform and then as adults they don't know much else and so simply continue - I speak generally of course.
Common sense is one thing yes, but that's not the only reason people use to stay in place, there themselves or inhibit their own growth. There's a lot of excuses for lack of progression...most are just bullshit though.
It's interesting how generations seem to go to extremes to undo what they perceived were the errors of the previous one. From overly protective to out of control and back again.
Yeah, they call that human progression.
I see it as stagnation; nothing new, just the old rehashed.