I had an experience in the garden last year that I won't forget. Call this "I wish someone had told me".
When I saw a fuzzy white insect on one of my plants my brain said "Mealy Bug; Kill It" and I instinctively picked it off the plant and squished it.
Having second thoughts, I looked again at the plant. Oh, no, what have I done?
I killed a Cryptolaemus montrouzieri which is a 'Mealy Bug Destroyer'. I won't make that mistake again. Yep, I wish someone had told me.