A lot of people like the image of the archaeologist. Sometimes more than they like archaeology itself. A tattoo is a fine way to proclaim your commitment to being a 'cowboy of science'.
(Though I am concerned. This looks like one of those horrible tiny euro-trowels, rather than a proper Marshalltown).
How much of our love for archaeology is about building a personal identity as an 'archaeologist'? How much of it is really about the work of interpreting, publishing, and teaching?
Is archaeology a 'lifestyle choice'? Is it part of your 'personal brand'?