Here's my understanding of the whole muscle tiredness, burning, and rest thing:
First of all, its important to distinguish between your legs "burning", and your legs "aching". When we use muscles very hard, such as climbing on a bike, we are doing anaerobic exercise, which builds up lactic acid in our muscle cells. Lactic acid is cleared by muscle motion. A long time ago I discovered that when cycling hard, if I took 20 second breaks to rest my legs, they felt much better when I started up. However, if I take longer breaks, my legs "burn" when I start. By "burn" I mean a quite severe pain with a burning quality, that does ease up and disappear after a while if I keep cycling.
I've now come to understand that this burning is the result of lactic acid build up, and the burning pain is what we feel as the lactic acid is cleared. It can be quite painful. It can be avoided by taking very short breaks, and also by cycling in a way that keeps your legs moving, and thus clearing lactic acid. For example, when cycling over rolling terrain, during the downhill segments keep your legs moving, but not pressing at all.
On the other hand, if your muscles are just overworked, they ache. This is the typical ache we all feel the morning after a hard, long ride. My understanding is that this pain, often characterized by a tenderness in our thighs, is actually the result of inflammatory damage to our muscle cells, and typically takes a couple days to repair itself and resolve. After exercising our large muscles for an extended period, such a cycling hard, the circulation to these muscles stays elevated for about an hour after stopping, and during that time a recovery drink can be of benefit in repairing the muscle damage, and thus minimizing the pain the next day. After an hour or so, when your circulation has returned to normal, recovery drinks are of less use.
I suspect that in fact your experienced burning due to lactic acid build up. The fact that it finally resolved later, after you had coincidentally eaten the burrito, is just due to enough time that the lactic acid finally cleared from your large muscles. If you had been experiencing aching due to real muscle fatigue and damage, it probably wouldn't have cleared so soon.