Ah, you forget Mary Magdalen was there too. She was a woman who loved Our Lord very much. I doubt she forgot about anything that had touched His body. She and her friends probably gathered up the linen keepsakes out of love and reverence. It’s something women do.
Feeling as they all did about Christ, after having heard His words about His blood, they probably regarded the burial linens with His blood all over them as sacred from the very first moments.
I forget no such thing.
...they probably regarded the burial linens with His blood all over them as sacred from the very first moments.
Practically the first thing that Joseph and Nicodemus did with the body after getting it from the Romans would have been to wash it completely. I don't suppose that the body had been completely exsanguinated, but the fact that "blood and water" issued from the spear wound (inflicted after death) showed that the blood had already started to coagulate and settle. There would be no blood on the graveclothes.
Between Calvary and Ascension Day, the disciples saw Jesus repeatedly. I doubt very much that they bothered at all with either the tomb or anything in it, after they had seen the Lord Himself alive again. Mary Magdalene grabbed Him by the ankles on their first meeting after the Resurrection, as if never to let Him go. She, of all people, would be the last to concern herself with a bundle of discarded textile products — at least, until it was too late for going back to look for them. Especially ones that had been on a dead body, which would make them ritually unclean.
As to what the disciples understood about the meaning of Christ's blood, they heard him talk about it, but it was over 50 years before John wrote most of it down. It took years for the disciples to understand it. At the time, they understood practically nothing, as we can see from the Synoptic Gospels. They were completely blindsided by the Crucifixion, despite repeated assertions by Jesus that He was going to Jerusalem to suffer and die. The Resurrection caught them no less "on the hop", again despite repeated statements from the Master. Ironically, it was the authorities who took more note of those predictions than the disciples did, since it was they who posted a security detail on the tomb.