Expiration payoff vs Today's P&L

The solid line is profit and loss if held to expiration. The dashed line is the position's value if the underlying moved there right now, time value included. The vertical gap between them is time value, and watching it close as expiry approaches is the point of the chart.

Breakeven dots mark every zero crossing. What-if scenarios (shift time forward, move implied volatility, or both) each draw another dashed curve, so you can see the position age before you put it on.