Mike Israetel classifies beginner as someone who can make weekly progress on lifts, intermediate – monthly progress and advanced – someone who needs to pull out all the stops to continue making smallest of increases. You can also be “beginner” for some muscle groups/lifts but intermediate on others. I find this to be the most helpful way in terms of identifying what specific techniques I may need to be using to continue seeing progress rather than just relying on years in training.