Joy is an inward flow from within even without any physical engagement. Is different from being happy, it can expire in time but joy can not expire, is an inward flow. Scripture said about laughter that at destruction and famine, you will laugh 

Job  5:22 At destruction and famine thou shalt LAUGH: neither shalt thou be afraid of the beasts of the earth.

This is not normal. To laugh at destruction and famine. This will be times when men will frown their faces and complain about everything they see. But, scriptures said at that time thou shall laugh! Glory to God!

Joy produces an inward laughter that boast out without fear from the heart to the lips. Scriptures refer to it as a oil of joy.

Isaiah  61:3  To appoint unto them that mourn in Zion, to give unto them beauty for ashes, THE OIL OF JOY for mourning, the garment of praise for the spirit of heaviness; that they might be called trees of righteousness, the planting of the LORD, that he might be glorified.

When something is an oil, you can’t hold it back but to boast into it. This is because, it will become a lubricant that brings out the outflow of joy from within. Joy therfore becomes what you go out with! As you move out, you move out with joy! I’m sure it will affect your environment! 

Isaiah  55:12  FOR YE SHALL GO OUT WITH JOY, and be led forth with peace: the mountains and the hills shall break forth before you into singing, and all the trees of the field shall clap their hands.

To therfore consistently enjoy the flow of this joy we must therefore stick to the Lord, who gives the joy unspeakable. By staying in constant fellowship with Him. For as we abide with Him, we will always come out with joy.