Try not to "read a book by it's cover". Actual experience is worth much more. How do you know for sure you will have a difficult time?
We did our first Viking cruise, and did not even think about it when I booked our excursions. Most were "included" and some were extra pay. Not once did I find a sold out excursion, and I did not book at first opportunity...but had waited awhile, finally booking once I thought about it.
The whole Viking Experience was one we loved so much, we now have another 5 booked and searching for more to add to the line up. My glass was "half full"....now it is all the way up there. 😉