It's more about the usage. When you say in Russian "I gave flowers" it sounds unspecific, because, ultimately, you made your girl a present with those flowers. So she's the end user. But when you just "gave", perhaps your intention was that the girl would do something with those flowers, like decorate your house, or give the flowers to somebody else.
Exactly. Because, if you say "я дарил цветы" that would mean "I used to give". I know, the perfective/imperfective might be a struggle, but try to use the following rule: in a place where you can say "used to" in English, use imperfective in Russian; otherwise use perfective. In your sentence, you used "дал" and not "давал" correctly perfective-wise.![]()