I think the title name strawberry swing is referring to an attitude, or feeling more than an actually swing. Strawberry is a fruit which could be symbolic in some way, and also the color, and swing is a motion or a dance perhaps. Also he mentions "every moment was so precious" this makes me think he cherishes every moment, and "wouldn't wanna waste a thing." also "such a perfect day". Next. "sky could be blue." when you think of a sunny day you think of happiness, and when its raining and cloudy you think of depression. He is saying that in all days (sunny or cloudy) the day is perfect. Also without her there it doesn't matter what the weather is. When he says "everybody was for fighting" he might be pointing towards caring about the important things, and not the stupid stuff people fight about now days. This could be related to a couple who were together, and one of the two were leaving to go thousands of miles away, and in that time they were together they enjoyed every moment more because they knew they're time left was short.