I hate single strand knots, every now and then I will find a few and cut them off. I didn't even know what a single strand knot was before I began wearing my hair curly nor had I ever had one.
There is an article on here about it. It says:
Fairy knots are teeny tiny knots that form on the ends of strands of hair, especially highly textured hair. They can appear after frequent manipulation from styling and even sometimes from constantly doing wash-and-go’s. Resist the urge to pull or break them off as this will only cause more breakage. Instead, grab a pair of scissors and snip the knot. If left unchecked, these fairy knots could cause more tangles and then become a nightmare to deal with. In the long run, your curls will thank you for trimming them off.
I know if you leave them in it can make the strand weak so try to cut them off when I find them. Sometimes mine are not even at the end they are further up the shaft. I don't get many but they are a hassle sometimes.