According to what I read at Ohio States website (I just googled Brown Recluse Spider), some people show no reaction at all, some show a drastic reaction. It depends on how much venom is involved and how sensitive the person is.
Personally, I was bit by a black widow when I was in the Air Force. Didn't even realize it until the next day, and all I had was some redness and swelling at the bite.
Wow, you're lucky, Bob. I was bitten on the neck several times, next to the juggler vein and within fifteen minutes my entire abdomen was in severe cramps and I had a headache that felt as if my head would explode. After getting to the hospital, I was morphined into a state I don't recall much for the next two days. For six months afterwards, my legs felt like jelly - sometimes not as badly as others, but increasingly got better. Don't know if the leg weakness was from the venom or morphine.