Be ready for the day of commitment. The day you try a river one class larger than you've been paddling, and you get your ass handed to you. Maybe it will be one swim, or a series of swims, window shaded in a hole, foot entrapment, arguments within your group. For some you might just get the shit scared out of you, or you will witness something as bad or worse happen to another paddler.
All of a sudden, your perspective changes, and you must commit, or sell your gear. The day that happens, should you commit, you will be a better boater.