LTH - an example for you (what a suprise, it's a fever remedy)
If you eat lots of chamomile flowers, you will be very ill. Different people become ill in different ways, but common symptoms are a high fever, earache, toothache, one red cheek, one pale, immense irritability, impatience and temper, a compulsion to walk about, anxious dream, drowsiness without being able to fall asleep....
Many people drink chamomile tea - as an aid to relaxation. It helps "cure" irritabilty, and can aid sleep. In this way it is acting almost homepathically - it's a dilution of the original substance - but, if you drink lots and lots of chamomile tea, it can actually make you more stressed and stop you sleeping.
The homepathic remedy chamomilla (which is an extrememly dilute form of the plant) will cure all the given symptoms. It is often used for babies with teething pain - you know when they get into that really whingy grumpy state, reaching for things then throwning them away - that's classic chamomilla.
The best (non hippy-dippy) explanation I've been given so far is that when we are ill, it's because our immune systems can't fight off the casue of our illness because for some reason they don't recognise it. Giving a homeopathic remedy that causes similar symptoms gives the immune system a nudge to tell it what it needs to be fighting. It can recognise the remedy, and in marshalling it's forces to fight off the remedy, it inadvertently cures the original symptoms as well.