Oh, position your left pedal at about 3 o'clock, crunch down on the rear brake lever, and climb on. If you still need a ladder or step stool, by all means use it. I hate trainers, by the way. I may have mentioned this before.
I don't laugh at the ladder. I used one for a month after an injury. What a joy to graduate to curbs. Getting on and off unassisted was frightning, by the way.
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Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.