> disheartening to use a bunch of effort only to find it wasted

It's disheartening if your life plan was to do this for 4 hours then never again. But if you meant to keep using this skill, today's hard-won knowledge, combined with continued use, means he'll personally be able to eyeball a similar disassembled float-conversion function in the future and have an educated guess at its purpose, which is a super power!