Love is all about the little things. When you are really, truly, in love, you don't feel the need to dress up for them. The most important thing is being with them. Butterflies are not usually present in love. You should not feel nervous when you really love someone. Love means you connect with them spiritually, intellectually, and emotionally. And love means differences, disagreements, and arguing (but not fighting) because who wants to be with someone who is the same as they are? You feel refreshed when you are with them, but not necessarily weak when you are away from them. If you think about them all the time, always, it is probably lust or infatuation, not love.
The most important thing you should consider is, can I say 'I love you' and truly mean it?