When I say I love you, I might not. When I say you mean everything to me and that I couldn't live without you, I might mean that I'll forget you in a year. When I say you are my best friend, I might hate you in a matter of seconds. Nothing I say is definite.
But when I hold your hand, and feel your fingers in mine, and maybe our breathing is synced, and our eyes are locked, and our hearts beat in a rhythmic war (rivaling the emotions in our gazes), maybe then, I mean everything I've said (and then some).