We haven't joined our mind with the Nami. Nam means Krishna's name Nami means the one residing in the name. Krishna is in His name, but do we think of Him while we're chanting His name? Not fully. So when Tulsidasji says, “Remember the name once,” he means with full faith knowing that Ram is in this name, Shyam is in this name. Then once is enough. The point of all of this is whatever form of physical devotion we adopt, our mind should always be in God. That's the key. This is sadhana, joining the mind to God.
Where's the mind most of the time? In the world. Worrying, thinking, planning, desiring, doing something in the world. So it's busy all the time. The mind takes on the qualities of the thing it mixes with. So if we want to mix our mind with God. We have to bring God into our mind slowly by thinking about Him over and over again; He starts to infuse into our mind. And we start to take on His qualities. We start to experience bhav bhakti as our heart purifies due to becoming more and more joined with Him. And the means of doing this is called roop dhyan. This is the key: If you add roop dhyan to any spiritual practice whether you're offering something to God, cooking for Him, doing His arti, chanting His name. If you add roop dhyan, then you're going to get the benefit of that purification. Roop dhyan means thinking of the form of God. So if you are worshiping Krishna you have to think of Krishna's form when you're doing His arti or chanting His name or any form of devotion. That is the key and this is what almost nobody knows. People spend their whole life following such a disciplined devotion.
“I get up every day and I do this much puja and I recite these mantras!” The discipline is admirable, but then they're mystified, “Why am I not changing inside? I'm doing this devotion for years!” It’s because they're doing it as a type of physical practice. They're not adding roop dhyan into it. Before we do anything, we should always think of the form of God.
“Okay, Krishna! I'm going to chant Your name! First, You come in front of Me. Now.” I'm thinking of Krishna. He's already here. There's no obstacle in creating that connection with Him. He's already here. He's even inside our mind. He's inside our soul, but we have to create that conscious connection with Him and then maintain that awareness of His presence while we're doing devotion.