I have a number of Bic lighters that are at least 10 years old. I bought a big box of them when the child-resistant requirement came in.

So far they've been flawless. But I just had two of them fail on me in the last month. Butane and valve are fine. But somehow the flint seizes tight in its tube, so no spark. I tried everything, including cutting the holding tube with an Exacto blade. No luck.

So check your gear regularly. Bics have a lifespan. Who knew?