Explanation for Murphy's law?

More often then not you could put in down to confirmation bias, a cognitive bias where people basically remember information selectively, or interpret it in a biased way. Another way to think of it is we tend to remember the "hits", but forget all the "misses": https://en.wikipedia.org/wiki/Confirmation_bias

Another component may be the Law of Truly Large Numbers: "The law of truly large numbers... states that with a sample size large enough, any outrageous thing is likely to happen. Because we never find it notable when likely events occur, we highlight unlikely events and notice them more." https://en.wikipedia.org/wiki/Law_of_truly_large_n...

So it's not the universe out to get you, it's just probability taken personally.

it happens but humans just put a name to it. Life can have times where murchys law seems to be happening.

It might be tied to entropy