I think one important thing to note is it's a lot easier to ride over your head on an MX track compared to single track. At least that's been my experience here in the NE.
I personally don't tipically ride over my head. Sometimes I crash but so far I've never had very serious injuries. I should point out some things to explain my experience and my point of view:
First of all, I am a slow rider and overall my experience is something like 200 hours at private tracks of MX and supermoto combined; supermoto done mostly at a track with jumps on asphalt.
I am also a risk calculator, I am not reckless in general. From my past experience both on public roads and at the track, personally I think I am better than the others in managing my emotions; I've seen smart people doing pretty stupid things with motocrcycles. What I mean with "stupid things" is not doing an extreme scrub on a jump face if the rider knows what he's doing, hopefully one day I'll do that, too, but rather exceeding one's limits a lot or endangering the others a lot.
I also never race since I find that it adds some fun but way more danger, especially because it's hard to calculate risk when risk depends on your interaction with others.
Talking about trails vs MX tracks: you see, the surface of a MX track does change during the day but it does it gradually and so it happens seldom that there is some unexpected feature that endangers the rider. A new hole doesn't appear all of a sudden, it becomes deeper and deeper after every lap, so it creates risks that can be estimated decently.
I listen to AJ Catanzaro's advice and, especially considering that my experience is limited, like he suggests, I work a lot on technique and not so much purely on intensity and I think that I will always work at least a little bit on technique; he says pros still do it a lot despite their already very good skills. To me, it seems that by focusing on technique I am getting faster and faster; it's taking time, though.
And don't get me wrong, although I get passed easily, I have so so much fun!