Not all of us are born into a family of gardeners who can pass on experience. And taking on an allotment is a game of chance because you have no idea what you are getting or what the last tenants over many years did or didn't do to it. I suspect that's why so many people give up so easily
And the book never tells you in plain language what you can do wrong!
My daughter came back with some strawberry runners a couple of years ago from her friend's house which she said were excellent fruiting. I trusted her with the planting out as she had done really well with planting up shallot sets and her own garden but was not good idea with strawberries. She planted all the plants up with a solid root ball instead of washing out the roots to allow them to spread and was then disappointed with the results.
I discovered the problem when I lifted the lot in order to add compost to improve the bed - we'd blamed the clay soil and a season of floods, cold and wind along with lack of compost to put into all the beds. Such is life - the plants survived and cropped a bit that year, did far better with the compost last year but I've quietly planted up the bed with runners from said plants along with still more compost and they are now thriving. Don't tell the daughter though as we want to keep getting freebies.
Now over two years I've managed to grow root crops of all sorts, marrows, courgettes, peas and runner beans in plenty but have failed miserably with cabbage, calabrese and purple sprouting broccoli. At which I blush as I'm third generation of gardeners. It's a case of two things I think - lack of lime and not firming up the soil enough or stupid grower. So can only do better this season - maybe perhaps.