I walk all kinds of stuff now.
There is one spot on my ride, where there is a steep bank you have to get up after a sharp turn, so you really have to stomp on it to get up. I can do it, or I could a year ago. Now it just doesn't seem worth pulling a groin for it.
There is also a bridge with no railing and it's at a SLIGHT angle to the trail. It's just a small hop to get up, but if the wood is the slightest bit damp, I walk it. One time a few years ago, I didn't, and I was REALLY lucky I didn't get hurt. Front tire slid out, I went head first into the culvert, with my bike landing on top of me.
NEVER again.