Don’t listen to him. Always wear your life jacket when in a boat.
Even the best of swimmers can be knocked unconscious when falling out of a boat. Even in warm water you can become exhausted and drown if in the water long enough.
A life jacket does you no good if you do not wear it.
Good luck getting a fisherman who is just paddling or slowly trolling along a lake shoreline to wear a life jacket. When the water is warm, they’re not going to do it. Even when it’s cold they probably won’t, although they should.
It’s a no brainer when you’re paddling in a river with current or running a powerboat in a lake or salt water.