Wow - you are a dear to have done that! I think you learned a lot in the process - I hope your co-worker appreciated the work you did on that.
I have learned - the hard way - to always ask to see what is involved before committing to doing anything.
If it is something like what you have just described - I try to avoid it like the plague. My life expectancy is too short to deal with things like that now. (Maybe - just maybe - for one of my kids or grandkids - other than that, NO NO NO!)