A tourist walked into a pet shop and was looking at the animals on display. While he was there, another customer walked in and said to the shopkeeper, "I'll have a Geologist monkey please."
The shopkeeper nodded, went over to a cage at the side of the shop and took out a monkey. He fitted a collar and leash, handed it to the customer, saying, "That'll be $5000." The customer paid and walked out with his monkey.
Startled, the tourist went over to the shopkeeper and said, "That was a very expensive monkey. Most of them are only few hundred dollars. Why did that one cost so much?"
The Shopkeeper answered, "Ah, that monkey is a GIT - geologist in training - it can lick rocks and tell you the exact mineralogy, well worth the money."
The tourist looked at a monkey in another cage. "That one's even more expensive! $10,000! What does it do?"
"Oh, that one's a P. Geo - a professional geologist - it can log and drill wells, update and construct geological models, they are experts in igneous and metamorphic petrology and petrography, hydrogeology, sedimentology and structural geology. SOME can even do basic calculations. All the really useful stuff," said the shopkeeper.
The tourist looked around for a little longer and saw a third monkey in a cage of its own. The price tag around its neck read $50,000. He gasped to the shopkeeper, "That one costs more than all the others put together! What on earth does it do?"
The shopkeeper replied, "Well, I haven't actually seen it do anything, but it says it's a petrophysicist..."
Full disclosure: My title at retirement was "Senior Petrophysical Associate"