probably it will get over that when he starts to feel safe with you. When you handle him don't hasitate when you pic him up. Try not to feel scared to get bitten. In my oppinion snakes feel that and when you hasitate to pic him up he will be most likely to strike.
When you handle him often he will get used to you so he won't strike at you or piss over you
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Hissing can also go away allthough my snake sometimes hisses at me when she just doesn't want me to tuch her. Just handle him easy and let him feel safe.