" I don't really worry about them anymore."
You should. The Lyme disease is not always so easily diagnosed, and if it progresses for a while, may leave you permanently disabled. Finis, BP.
The prevalence of Lyme in deer ticks is very high here in NH, although the studies run all the way from 20% to 50%. Fortunately, they can still be avoided by going north of the Whites to the Cohos Trail, but they move further north every year.
It would make sense to do a little research and find out how prevalent Deer Ticks, as opposed to other types, are in your area; and if so, how infectious they are. State health departments can be very helpful with this type of info.
Hiking here around Chocorua in the warmer seasons, I stick to the hardened trails below 2000' and spray Permethrin on boots and clothing, but not directly on skin. You're right, the ticks aren't fazed much by DEET, and won't let it keep them from a happy meal. Were I camping here, I would spray the gear, all of it, without hesitation. My dogs have lyme shots, and are treated regularly with Frontline, but still get dog ticks. The Deer ticks are much harder to detect.
Wish a new human vaccine for Lyme would be reintroduced.