Amazing equations!

When I was a school student these were the equations I was totally confused and amazed about:

c = 1 /√(μϵ) ---------- 1

I was confused what does speed of "normal" visible light has to do with current or magnet!

E = mc^2 ------------ 2

I was amazed this time, what the heck speed of light has to do with Energy! I didn't believe this 'c' is the same as speed of light the first time!

Amazing!