I just don't see how you can use była in a sentance that makes any sense when talking about eating cucumbers.
Because the verb
być refers to existence, i.e., the situation which exists now (present tense), which existed before the present (past tense) or situations which will exist (future tense).
The existence we are referring to in this example is whether a cucumber is being eaten, was eaten at sometime in the past, or will be eaten (or, indeed, whether or not it should have been eaten!).
Hence if you wanted to say (a silly example, I know ;) ) "It's good to be a cucumber" it would be "jest dobrze
być ogórkiem", but this changes to "dobrze
było być ogórkiem" (i.e., it was good to exist as a cucumber
in the past), or if you are planning to become a cucumber one day, "dobrze
będzie być ogórkiem" (i.e., it will be good to exist as a cucumber,
in the future).
Beyond that, I think you need a teacher to explain it; I'm definitely not a teacher ;)
Polish grammar often makes things sound complicated, whereas English makes it a bit more logical; but at least Polish doesn't have words with silly pronunciations like "Leicester" or "Cholmondeley" - difficult grammar is the trade-off for easier pronunciation ;)
but still dont understand what the hell this has to do with a cucumber...
Because in the context of the verb
być, the situation the cucumber is in (past, present, future) is more important than the cucumber itself ;)