Your descriptions made me laugh. It sounds adorable, but is probably not so cute at 3am when you're exhausted.
All babies are different. It sounds like this is just the way his brain is wired and there may not be much you can do about his waking patterns. My only suggestion is, if you're not already, to make a very clear difference between sleeping time and awake time. Get black-out curtains so there's total darkness during sleeping time, including naps, and keep them open during awake time. White noise is great. We turn on rain sounds to set the mood for sleep for our kids, and turn it off right away in the morning. We're very consistent with the white noise so now when we turn it on (we use an app on our phones called Nature Sound) there is no question that it's time to sleep. Bedtime routines are good for getting him in sleep mode too, then for night wakings you could repeat a part of the routine to get him back down.
If he is napping a lot during the day that might be why he is waking up at night so much, and waking fully alert--if his sleep needs have been met during the day then he just won't be tired. If this is the case you could encourage fewer or shorter naps--I wouldn't wake him from a nap if you think he really needs the rest, but you could gently try after he's been sleeping for an hour or whatever, and see if he wakes up. Then chances are he will make up that "lost" sleep later that night.
No matter what, be very very grateful for those 6-hour stretches!! Those are very rare for my kids, now 2.5 years and 9 months. I've probably slept 6 consecutive hours less than 10 times in the past 3 years, so you are definitely lucky there!