The difference between ありきたり and 平凡?


Both of them are Na-adjectives and both mean "ordinary, common". Are there any
differences?

I saw a sentence:

> そんな平凡でありきたりなことじゃないのかも

Why "平凡" and "ありきたり" are both used here?




「平凡{へいぼん}」should mean "mediocre" and「ありきたり」should mean "frequently/often
happens" here.

So, "ordinary, common" is not off. Probably the author would like to mention
that things are not the routine.

In other words, it's like [normal
distribution](https://en.wikipedia.org/wiki/Normal_distribution) in
mathematics. You will very likely to encounter a mediocre thing in the world,
but at this time it is different.

