I have repeated maybe twice in my life.
It strikes me that this might be a more universally ignored instruction than the speed limit.
What say you?
Very, very rarely. I don’t know why shampoo manufacturers even bother. I doubt they even rinse and repeat in fancy-ass salons.
I think that may be true, but my shampoo says repeat if desired. I desire about once a week or if I get really nasty. I do find that if I don’t repeat occassionally, I run out of conditioner before shampoo, so… what the hey!
…and you shouldn’t need to re-lather. I think they wrote that just to sell more shampoo. If I feel a “build-up” in my hair, I use a clarifying shampoo.
Also, and I don’t know how true this is, I read in an old GQ mag that us guys lose enough hair as it is, why lather twice and risk losing more?
Quasi
I do. I also shower at least twice a day.
You bet. Usually, though, it’s just for fun. Rarely because I need to wash my hair the second time.
I followed the “Lather, rinse, repeat” suggestion just last week, since I had just installed a starter on a friends Rodeo. I wouldn’t have bothered, but there were still chunks of things stuck in my hair after I washed the first time.
Since I have The World’s Oiliest Hair, I have been known to “Lather Rinse Repeat”. But only rarely. You can’t take these things literally. As I have noted before on the SDMB, “Lather Rinse Repeat” is an endless loop.
Lather, rinse, repeat as needed.
I find that the second round of lathering is much more satisfyingly lathery. The bubbles seem to come up so much nicer once the first round of schmutz is removed from your funkified hair.
I agree. You get much nicer foam the second time and it feels cooler.
Yep, I have hair down to my waist, and I often repeat the lather and rinse part.
If I have been swimming in the ocean, I sometimes do it three times (yes, I know, I’m a wild woman) to get all the salt and sand out.
I tried “Lather, rinse, repeat” once, but then I found myself in an infinite loop. I’m never trying that again.
<------ Yes 
OK, first of all I think the instructions were put on the bottle just to make people use more shampoo. I actually remember when they started putting this on the bottle. Obviously people who need to shampoo twice can figure this out for themselves. The instructions are just to put the idea into the heads of people who don’t need to shampoo twice.
Still, having said that, a lot of times I do need to “repeat.” I have very oily shoulder length hair, and sometimes I have to wash it twice to get it clean. When it was waist length, I ALWAYS had to wash it twice.
i’m bald.
Due to a very thick head of hair and the nature of my job(rancher/farmer), after some jobs one pass just isn’t enough. The worst I can remember is replacing the power steering box on a 1975 F-700 truck. First of all the old box and most of the engine compartment had 20 years worth of leaked and spilled oil. Second, we were replacing it mainly due to not working right but also because it was leaking pretty good. We had to undo the motor mount bolts and jack the engine sideways to remove and replace it. The part in question weighs about 50 pounds or so and you had to get right up against it to get any leverage. After the new one was in we also replaced the hoses going from the pump to the box and that was a minor feat of engineering in itself using various elbows and lengths of hose that of course leaked when we tried it the first time. The only way to see where it was leaking was to lay almost directly under it. We managed to kill the whole day on this job and by the time we were done the stuff in my hair added about five pounds to my weight. It took at least three passes to get all the layers soaked through and scrubbed off.
After hiking and climbing in the mountains most weekends, I lather, rinse, and repeat to get out all the dirt, and oil. It’s even worse after a week or two in the woods. 
I rarely lather, rinse and repeat but when I do I can tell the difference the second time around. The lather quotient is much higher and my hair generally feels softer.
i’ll do the repeat once or twice a week, but i got long ass hair and do lots of dirty stuff, so it generally needs it.
After a weekend of camping I’ll lather up at least twice. Usually, it’s just once though.