Not only memories but also specific intentions for action are unlikely to be well retained in the mind over long periods of time without conceptual language. There is an assumption that language did not originate as a means of communication in the first place, but as a tool to enable intentional and coordinated action in the group at a higher level. Sending someone out in search of food when they are not immediately driven by hunger, without them following another impulse after five minutes, is probably hardly possible if they cannot carry the task with them in their head in a linguistically fixed form.
