经典英文歌lemon tree 中的柠檬树指代的是什么

谢谢帮助!

应该是恋爱那种酸酸的心情吧

有酸有涩，喜欢就是甜，拥有才是幸福。

爱情

i’m sitting here in a boring room(我坐在屋里，百无聊赖) it’s just another rainy sunday afternoon(这又是一个雨天的周日下午) i’m wasting my time, i got nothing to do(我在消磨着时间，无事可做) i’m hanging around, i’m waiting for you(我来回徘徊，在等待着你) but nothing ever happens, and i wonder(可你却没有来，我疑惑不解) i’m driving around in my car(我开着车去兜风) i’m driving too fast down, i’m driving too far(我开得很快，开得很远) i’d like to change my point of view(我想改变我的想法) i felt so lonely, i’m waiting for you(我感到很孤单，我一直在等着你) but nothing ever happens, and i wonder(可你却没有来，我疑惑不解)) i wonder how, i wonder why(我想知道你怎么了，我想知道你为什么) yesterday you told me about the blue, blue sky(昨天你告诉我那蓝蓝的的天空) and all that i can see is just a yellow lemon tree(但我所见的，只是一棵黄色的柠檬树) i’m turning my head up and down(我摆动着我的头，上上下下) i’m turning, turning, turning, turning, turning around(不停地摆动着我的头) and all that i can see is just another lemon tree(但我所见的，只是一棵黄色的柠檬树) sing,da,dadadada,dedada,dadadada,dedada,dadededa... i’m sitting here, and i miss the power(我坐在这，身上失去力气) i’d like to go out taking a shower(我想出去洗个淋浴) but there’s a heavy cloud inside my head(但是有一片阴云在我心中) i feel so tired, and put myself into bed(我感到很累，躺在床上) where nothing ever happens, and i wonder(那没任何事情发生，我疑惑不解) isolation, is not good for me(孤独，我不想这样) isolation, i don’t want to sit on a lemmon tree(我不想继续孤独地守着一棵柠檬树) i’m stepping around in a desert of joy(我快乐地漫步在沙漠中) baby, anyhow i get another toy(宝贝，不管怎样我要去找别的快乐了) and everything will happen, and you wonder(将会发生什么，该你去想想了) i wonder how, i wonder why(我想知道你怎么了，我想知道你为什么) yesterday you told me about the blue, blue sky(昨天你告诉我那蓝蓝的的天空) and all that i can see is just another lemon tree(但我所见的，只是一棵黄色的柠檬树) i’m turning my head up and down(我摆动着我的头，上上下下) i’m turning, turning, turning, turning, turning around(不停地摆动着我的头) and all that i can see is just a yellow lemon tree(但我所见的，只是一棵黄色的柠檬树) yellow ? wonder, wonder. i wonder how, i wonder why(纳闷，我想知道你怎么了，我想知道你为什么) yesterday you told me about the blue, blue sky(昨天你告诉我那蓝蓝的的天空) and all that i can see(但我所见的) and all that i can see(但我所见的) and all that i can see is just a yellow lemon tree(但我所见的，只是一棵黄色的柠檬树)