The “man with a hammer” tendency (also called the law of the instrument, Maslow’s hammer, or déformation professionnelle) is a well-documented cognitive bias in psychology: once you acquire a particular tool, skill, or framework, you start seeing almost every problem or opportunity through that lens and over-apply it.
Abraham Maslow phrased the classic version in 1966:
“I suppose it is tempting, if the only tool you have is a hammer, to treat everything as if it were a nail.”
The same idea appears earlier in Abraham Kaplan’s work and in observations about professional deformation (the way a profession shapes perception). In my woodworking example, the new skill becomes a powerful organizing frame: every object, space, or need is unconsciously filtered for “Could I make that out of wood?” or “Is this a joinery/problem that woodworking can solve?” The frame feels productive and exciting because it is newly fluent and rewarding, so the mind keeps returning to it.
Why this happens psychologically
Availability and fluency: Newly learned skills are highly accessible in working memory and feel easy to use. The brain prefers fluent solutions over less-practiced ones (processing fluency bias).
Confirmation and selective attention: Once the frame is active, you notice confirming instances (things that could be wood) and overlook or downplay alternatives. Attention is finite; the dominant frame crowds out others.
Identity and motivation: Mastering a skill often becomes part of self-concept. Applying it everywhere reinforces competence and identity (“I am a woodworker”), which is intrinsically rewarding.
Problem-solving shortcut: Complex situations are simplified by mapping them onto the familiar domain. This is efficient when the match is good and distorting when it is forced.
Expertise effects: Specialists routinely show this (doctors who see every symptom through their specialty, software engineers who want to code everything, etc.). It is not limited to novices; deep expertise can intensify the myopia.
Related concepts that capture the same phenomenon:
Functional fixedness (Gestalt psychology): difficulty seeing an object or method outside its usual function—here inverted so the tool is over-generalized.
Einstellung effect: a familiar solution set blocks better or more appropriate approaches.
Professional deformation / occupational psychosis: the occupational lens becomes so strong that it colors non-work perception and judgment.
Confirmation bias and narrow framing in decision-making literature.
The double-edged nature
The tendency is not purely negative. It drives rapid skill consolidation, creative recombination within the domain, and the “maker” impulse that produces real objects and competence. Many useful inventions and hobbies begin exactly this way. The downside appears when the frame becomes rigid: you miss better materials or methods, invest disproportionate time, or misjudge problems that are not nails. In extreme form it can look like monomania or reduced cognitive flexibility.
Softening the lens (without killing the enthusiasm)
Awareness itself helps. Explicitly asking “Is this actually a wood problem, or am I forcing it?” introduces metacognition. Periodically forcing alternative frames (what would a metalworker, a 3-D printer, or a pure minimalist do?) or deliberately practicing other skills keeps the mind less monopolized by one tool. Time and broader experience usually dilute the intensity of the new-frame effect as the skill becomes more integrated rather than dominant.
In short, the woodworking-everything phase is a normal, predictable product of how attention, fluency, and identity interact with a newly acquired capability. It is the mind doing what minds do when they get a shiny new hammer.