For some reason, it really boosts my self-confidence when I see someone else trip while walking down a sidewalk. If nothing else, I know that I can at least walk better than that person.
Suck on it.
Oh, but I’ve been studying. For something relevant, I’ll draw an amino acid…how about histidine (HIS/H) at pH 7.4? Its pKa is 6.0, so it lacks its proton at 7.4. 🙂