I realize this is an old thread, but it is the first one I read and I had to comment! I have no idea on the "why" of jelly strands though I believe I know what you are referring to. It was never an area of interest for me, or him. And I am interested in penises.
However, I for one cannot stand the "tapioca" (perfect word for it) texture. I always thought it occurred when the man had not orgasmed for a few days. And honestly, and now that I'm saying this it sounds silly, I though the chunks were sort of like dried ejaculate. You know, like on on the bottle of dish soap...the part of the soap that is exposed to air...
And THAT is a huge reason I didn't like them. I'm fond of ejaculate but not old stuff. Just like I don't want the crusty pieces atop the ketchup bottle.
Now that I know it is normal, well, I was going to say I would be more open-minded, but truthfully, I'm still not going to like it. 22 years+ of them and I'm not going to do chunks, at least orally. If we have sex often enough then I know I can don't have to deal with chunks.
I'm glad to see that those who have them are not agonized by them, same about those with or without jelly strands. @goldeneye, I had not thought about chunks feeling good on their way out...that is cool and makes sense. Oh, and @OP, I know you aren't speaking of thick semen, but I've noticed that it seems to get thinner the more times a man ejaculates, all in the same 2-5 hour "event". But there is definitely an obvious difference between think and less thick.