18 years = 2 coins

"Once a famous yogi went to Ramakrishna Paramhans  who was sitting on the bank of the Ganga. He said, "Ramakrishna, what are you doing sitting here? Let us go for a walk over the Ganga." 

Ramakrishna asked him, "How many years did it take for you to walk on water?" He said, "Eighteen years practising in the Himalayas, hard work, fasting, yoga postures etc. Now I have this power to walk on the water. Can't you walk on the water?" 

Ramakrishna said, "I am not so foolish. When I want to go to the other bank I give the ferryman only two small coins, and that's enough! Your eighteen years are worth just two coins."