Start with the crust. Mix your graham cracker crumbs, melted butter, and sugar together until it looks like damp sand. Press it into the bottom and up the sides of a 9-inch pie plate, and set it aside.
Dissolve the Jell-O. Stir the orange Jell-O and sugar into your hot orange juice until it's completely dissolved. Now the hardest part: waiting. Let it cool until it's thickened and syrupy, about 20 to 25 minutes.
Chill your evaporated milk. While that Jell-O is doing its thing, pour the evaporated milk into a small mixing bowl and stick it in the freezer. You're waiting for little ice crystals to form around the edges, and that's how you know it's ready.
Whip it up. Take that icy-cold milk and whip it until it's nice and stiff, about a minute. Add your lemon juice and keep going until it's very stiff. It takes about 3 - 4 minutes in total. This is where the magic happens!
Fold everything together. Gently fold your whipped milk into the cooled, syrupy Jell-O. Be gentle here, you want to keep all that lovely air you just whipped in. Spoon it into your crust.
Chill and enjoy. Pop it in the fridge for at least 2 hours, or until it's set firm. Dollop some thawed whipped topping onto top of the pie, if you like. Then slice it up and enjoy every nostalgic bite.