It's true what they say: Even the savviest of love song writers need a nugget of relationship wisdom from time to time—and the same rings true for Taylor Swift.
Enter: Ed Sheeran (who celebrates his 23rd birthday today!), fellow award-winning performer and best friend. Swift credits the "Thinking Out Loud" singer for her a-ha moment. "Ed said something that really resonated with me," Swift candidly shared with us. "He says there are different kinds of love: There's physical attraction, mental attraction, and emotional attraction; there's also comfort and obsession. You need to have all of those things in one person. You have to mentally respect them, be physically attracted, and have a comfort level. You're obsessed with them, yet you also know they're going to stay." Sound advice! Wise beyond his years, indeed.