I am pathologically frugal, and I save used rear derailleur cables for front derailleurs. That proved not to be a winning strategy recently. It took me about two and a half hours to install a front derailleur cable because one cable was slightly crimped, and feeding it through the brifter was so tricky. The second cable's head was too fat, but I discovered it after going through the same tricky process. The third cable was brand new and took a minute or two. Maybe now I have learned and won't be polishing any more slightly corroded brake cables. But I won't be apologizing for patching inner tubes. I still think that makes sense.