We now use cave drawings as a record of what they saw/believed, that doesn't mean it was their intention do use them as records for. Other civilisations used a more advanced form of cave drawings (Hieroglyphs) and they used it to record their happenings, that doesn't mean it was their intention aswell.
We must remember that we are talking about a race that is ten of thousands of years old.
Probably communicated with grunts and hand movements. Had no though about there future and survival was their main priority, how to get their next meal.
The human race did not become the dominate species on the planet because we knew how to kill, we became dominate because of our creativity and one advantage over the lesser species – we used our brains. As like today some people are born more creative than others and it probably happened back then too. Certain individuals were born with more creative and developed brains and it was these people showing their creativity by painting on walls – showing their artistic talent.
Not all cave drawing were animals and such. Like with the aboriginal ‘dreamtime’ cave drawing. These were not pictures of animals, hunting or even humans, although they were human-like.


You know what those pictures look like to me? They look like the type of drawings that an artistic child would do on a painting - simple humans with little detail. Chances are they were and they passed through the generations. As generation got smarter the true origin of these paintings was lost (just a child doing a painting) and they gave these painting meaning and developed some of their beliefs on them.
JEEZ, this is a hard topic