taking pills against headaches can cause more frequent headaches

AAFP: Tension-Type Headache

Patients with chronic tension-type headache should limit their use of analgesics to two times weekly to prevent the development of chronic daily headache. If the patient requires analgesic medication more frequently, adjunctive headache medications can be initiated.

Cleveland Clinic: Tension-Type Headaches

There is no single cause for tension-type headaches. This type of headache syndrome is not a trait that runs in families. In some people, tension-type headaches are associated with tightened muscles in the back of the neck and scalp. This muscle tension may be exacerbated by:

Inadequate rest
Poor posture
Emotional or mental stress, including depression

Tension-type headaches can be triggered by some type of environmental or internal stress.

Cleveland Clinic: Rebound Headaches

The overuse or misuse of analgesic medications — exceeding labeling instructions (such as taking the medications three or more days per week) or not following your physician's advice — can cause you to "rebound" into another headache.
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Analgesic overuse appears to interfere with the brain centers that regulate the flow of pain messages to the nervous system, worsening headache pain.

This rebound syndrome is especially dangerous if your medication contains caffeine, which is often included in many medications to speed up the reaction of the other ingredients. While it can be beneficial, caffeine in medications, combined with consuming caffeine (coffee, tea, soft drinks, or chocolate) from other sources, makes you more vulnerable to a rebound headache.
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While small amounts of these medications per week may be safe (and effective), at some point, the continued medication use leads to the development of low-grade headaches that just will not go away.

Mayo Clinic: Rebound Headaches - Risk Factors

Your risk increases if you use combination analgesics, ergotamine or triptans 10 or more days a month or simple analgesics more than 15 days a month — especially if this regular use continues for three or more months.

Does Caffeine Cause or Cure Headaches? - On its own, it can alleviate some headache pain. It also causes pain relief medication to be absorbed better and faster. It can result in caffeine withdrawal headaches and rebound headaches.

How Much Caffeine is in Chocolate? - has a chart comparing dark chocolate's chocolate percentage (43 - 100%) versus caffeine content.

1 oz of 70% chocolate, which isn't unusual for me to eat, has about 40mg caffeine. That's similar to the caffeine content of a can of regular cola or a bottle of iced tea. A cup of coffee can have 100mg or more.

sighting

The person taking this video at the concert did a quick 360 degree turn to get the audience in the picture, starting at 40 seconds in. I found Qiao at 47 seconds, but not me. I guess I was too short.

"Karma Chameleon Culture Club Boston aug 2nd 2015" (Watch on YouTube)

Video Title: Karma Chameleon Culture Club Boston aug 2nd 2015
Posted by: Steamthetube
URL: https://www.youtube.com/watch?v=jKySajQDg3A

I believe that YouTube used to let you scroll through a video frame by frame. As of now, I can't find a way of doing that. There's a Chrome extension that apparently let you do it, but from the comments, YouTube made a recent change which broke that too. However, you can change the playback rate to 0.25 in the video settings (gear icon) to get slow-motion, and then you can press the spacebar to play/pause it.

These are some the keys that you can currently use to control YouTube video playback:
Left/Right Arrow: move 5 seconds back/forward
J/L: move 10 seconds back/forward
K or spacebar: start/stop play
1/2/3/etc - move to 0:30/1:00/1:30/etc
F - toggle Full screen