Answer:
There are many patterns:
1) Constellations, that is something like "Patterns" of stars, and people used to give them some bigger meaning than that (as they used to do with almost everything)
2) Time patterns: These are maybe the most useful, an example of this can be that in winter the time that the moon is in the sky is smaller than in the summer, so they already have some information about astronomy, other examples are things like comets and such, that also happened (and keep happening) in periodic time lapses.