I am at 4 years. Lay off for COVID. Just starting to get the hang of some things and present problems to higher belts. The interesting thing to me, once I can funnel someone into a dilemma game I know well, there isn't as much difference as I thought there would be between upper belts. I would say tougher black belts have seen it all before and give a really hard fight at each decision point in the attack tree, and can often just escape if technique is a little lose, but it isn't insanely different. I know how to fix things and make it harder every time I find a little gap like that now and they are little gaps. I still just get beat up most of the time, heh, but when things work they really work as I implement more of the game I like. I think that is an interesting place in skill development. Not an expert, but not a novice.