Life becomes more of a hassle when it’s not predictable. If what went up sometimes came down and sometimes just kept going up, it would be much harder to juggle. If trains came by whenever they wanted to, rather than keeping to a schedule, it would be harder to travel. If I had to guess whether the hot water was going to be on the left side or the right side of sink every time I met a new sink, I might smile a little less.
You get the idea. If books in the library were sometimes organized alphabetically and sometimes organized by color, then a lot less reading would get done. If the letter G sometimes came before the letter H and sometimes came after, imagine the havoc that would be wreaked.