Grob:
It's a bit late in the season, but I heartily recommend a trip to your local gliding club on a "good" (thermic) day - 45 degree turns are the norm and 60 is not uncommon, especially in the UK with it's narrow thermals.
BTW, as most gliders don't have an AH, 45 degree bank can be assessed by comparing the horizon to the mounting screws around the instruments which are conveniently at this angle.
I also agree with everyone else about the perception of G: If you're not in control, it feels a heck of a lot more dramatic than if you're flying yourself.
B2N2: "You should not be doing steep turns for an hour." - yes, it can be quite hard work, but this is not particularly uncommon for a scratching flight!
