It's a hard one but so is the road! Even after 6 months the scars from gravel rash will still be visible and sore.
All this can be avoided if you just don't wear your casual clothing whilst riding your bike. Even at the slowest speed, riding without proper protective motorcycle gear can leave you with third degree burns where your body has come into contact with the road. Gravel gets embedded in your flesh and can only be removed using tweezers, if at all (it may be so deep that you have to wait for it to work its way out naturally over several months!). You may also need skin grafts and will be scarred for life!
So forget your bikini or flashing your muscles. As well as your helmet, gloves and boots you need to wear a protective jacket and trousers. Think about getting some Kevlar lined jeans or combat trousers, you can even get a Kevlar lined hoodie with internal pockets for body armour!
Shorts and a Tee can be cool on the beach or around town, but on the road they are a sure way to gravel rash or worse. ALWAYS wear proper gear for biking. Summer riding gear still offers substantial protection but keeps you cooler. Keep a spare set of clothes at work or college and change when you arrive or leave.