Candle can be used for Heat. Heat is related to Like. Like is related to Stick. Stick can be used for Fuel. 
Forget is the opposite of Acquire. Acquire is related to Buy. 
Candle --UsedFor--> Heat <--RelatedTo--> Like <--RelatedTo--> Stick --UsedFor--> Fuel 
Forget <--Antonym--> Acquire <--RelatedTo--> Buy 