16 would be 👍 (going by the mapping in this post, or the pinky if you do thumb = 1).
4 is 4 either way.
Oh, for fuck's sake.
Your thumb is not your zeroth finger; it's your first finger.
Starting from zero is for situations when you're counting the left (or first) edge of containers used to hold items. For example, if you wanted to count the number of balls you could hold in the spaces between your fingers, you start with 0 because the number of balls you can hold between your thumb and {} is 0.
Indices vs offsets. A lot of people mistake the two because they took CS 101 and thought it was so cool to say I sTaRt cOuNtInG fRoM zErO.
length measures the spaces between the spaces between your fingers, so you can fit 3 balls between the 4 balls between your fingers
Also indexes. Once you've been bitten enough by off-by-one errors this actually becomes a pretty handy double-check.
Hmm. I use 1, 2, 4, 8, 16 (I seldom need to count beyond 31 (and have up to five more bits if needed), or to zero)
