I think you're right here, Anne. Over the years, we would have kept the stuff in good nick, and made sure we could use it again the following season, but, on one occasion, we were driving to Tunbridge Wells, past a layby, and I spotted a huge heap of debris netting, which had been dumped by a lazy builder!
We took a quick 'U' turn, and there was a boot-full of the stuff, perfectly clean, and clearly a new arrival in the layby that day, as it was still wet from the night rain!
Well, what would you have done! I still have some left, but most of it went to the new tenants, as their need was greater than ours!
As it was used as a double layer, we managed to keep the black seam-holes apart, to keep a continuous cover, but it worked for many years!