Lyme Disease is no joke. Left untreated, it will ruin your life.
Also, Lyme Disease doesn't always manifest in the usual bullseye mark. It can present as a fever, as a case of hives, and (most importantly) sudden muscle/joint pain.
Allowed to progress far enough and Lyme disease is also for life, potentially with permanent nerve damage.
To complicate the matter, current medicine is not very well equipped for diagnosing Lyme disease. I've seen a case of Lyme misdiagnosed as many things, including muscular dystrophy. You're on your own when it comes to noticing the symptoms and seeking treatment. You may also have to insist on being tested for it.
Be educated, avoid ticks, and look for signs if you're exposed to ticks.