Be careful with acetaminophen (aka Tylenol)  Overdoes can cause liver damage.  It is good at reducing fevers but no so great for "aches and pains" caused by inflammation.  It would not be my first choice of pain relief drug take backpacking.

Unless you have conditions that prevents you using it,   ibuprofen (aka advil) is a better over the counter drug for inflammation and pain control.  I have heard of it referred to jokingly as "vitamin I" by various backpackers.  It is also supposed to be helpful for altitude sickness.

What to carry depends on the length of the trip.  The most common "injuries" and "conditions" are dehydration, small cuts and scrapes, dry and cracking skin, problems with finger and toe nails, blisters, insect bites and associated allergic reactions, allergic reactions to certain plants, sun and wind burn, bowel issues, and chafe in the nether regions.

I'm not a First Aid guru but this is my working list. It is only an example and it may not be adequate for you so make your own informed choices.   You should also carry a suitable supply of any prescription medications you need and if you are allergic to bee stings, appropriate measure to counteract that. Women may require additional items for longer trips.

Short hike...Focus on dehydration, sun/wind burn and small cuts and scrapes

  • water and electrolyte hydration aids
  • bandaids for fingers and small blisters.
  • sunscreen
  • vaseline ( for windburn ) and dry skin
  • lip balm with sunscreen

Day hike or Overnight add...Focus on pain relief, allergic reactions, and foot care since you need to get home

  • ibuprophen (or if you can't take that, the pain reliever you can take)
  • benadryl tablets (allergic reactions)
  • leukotape for hot spots and for taping moleskin to pad blister.
  • some alchohol wipes
  • moleskin to pad blisters
  • needle
  • mini bic lighter
  • elastic bandage
  • small scissors and maybe nailclippers.
  • neosporin with pain relief (for small cuts)

Overnight or Multi-night add...Focus on bowel and chafing problems.

  • a few more of the above supplies
  • imodium tables (diarrhea control)
  • bismuth tables (indigestion, gas)
  • glide or similar (prevent chafing) 
  • desitin or similar (treat chafing)
  • foot/crotch powder with some fungus control (itching).
  • maybe one dressing for a larger wound.

If you are that badly injured you are going to need help and evacuation anyway

More remote and lonely trips will require more knowledge and supplies.

The trick is getting the quantities right.  You are unlikely to need the various supplies and unctions in the quantity/volume they are typically sold in so you probably want to re-package things.  This should not take up much space or weigh much.