I get asked that question a lot. Everyone that doesn't ride a bike seems to think that riding a bike gives you a sore bum.
Those are the same people that haven't ridden a bike in 10 years, pull the old rust heap out of the shed, pump up the tyres and go for a jaunt around the park.
The next day, their bum hurts.
So they think, "Sod this for a joke" and go back to sitting in front of the TV.
I'd say that the cause of the pain is the unexpected exercise, not the bike seat. I have been taking Monkey to the pool of late. The day after the first time we did some 'throw Monkey into the air' exercises, my shoulders ached like buggery. Which is not surprising, as it has been a long time since I have lifted any weight repeatedly above shoulder level.
Now, I can throw him up in the air with wild abandon and suffer no pain the following day.
That said, I do get a bit of pain towards the end of the week. It's not "bum pain" as such. It's just tired, worn out legs. I always have to remember to take it easy on Monday and Tuesday so that I don't feel like a wrung out dishrag come Friday. Of course I forgot that rule this week in a fit of madness when I chased a very fit young bloke up the approaches to the Anzac Bridge. I went up that slope in his wake at around 50% faster than normal, and boy, did I pay for it that afternoon.
I know that the only way to improve is to continually stretch yourself - the body can't be allowed to get into a routine as far as exercise is concerned. Chasing wiry young bucks is a great way to push myself out of my comfort zone, but bugger me, it gets harder as you get older.