As a human who isn't a professional programmer, I've been writing comments like,

    // let's track age!!
    // this is harder than you'd think as I with totally impressive
    // foresight didn't add age to the raw data.
    //
    // More honestly, I didn't want to add age to the astro data as that's
    // a calculation that can change depending on how you slice it.
    //
    // Hence we need to figure out their age first.
Is that bad???

// Workaround because we don’t have an age column in the db. See JIRA-1234

This would be better IMO :)

Most of the context belongs in a ticket. And the difficulty is subjective!