Apparent wind is not what you get from eating too many apparent beans, it's the term we use for the wind as you feel it on a moving boat.
Apparent wind is the wind you experience when the boat is moving – it’s the true wind modified by the boats motion. A 15 knot breeze coming at you from 45 degrees off your bow when you’re stationary becomes a 20 knot breeze at about 35 degrees off your bow when you’re moving forward at around 6 knots. The boat speed adds to the true wind speed, and modifies its angle of approach.
Conversely, when the wind is from behind its speed is reduced by the speed of the boat. A 15 knot breeze from dead astern is an apparent wind of just 9 knots when the boat is moving at 6 knots.
When you’re sailing you don’t really think about apparent wind – it’s the wind you’re sailing in and that’s that. However, there is a time when you really need to consider the effects of apparent wind and that’s when you change from a course off the wind to a course on the wind.
If you are running dead downwind at 6 knots in 15 knots of true wind and you then round up onto a close hauled course, the apparent wind goes from 9 knots to over 20 knots quite quickly. It can come as quite a shock! You need to be ready for it.