Unconditional love is known as affection without any limitations, or love without conditions. This is sometimes referred as true love.
There is a major paradox with unconditional love. Let's say you live your life loving everyone & everything unconditionally. Eventually you meet one or several individuals who will start to mistreat you, because they know you love unconditionally.
If you accept being mistreated, because you live your live with total unconditional love, then you lack self-love.
How can you unconditionally love everyone & everything, when you lack love for yourself?
What is the point of loving everyone & everything unconditionally, if you don't even love yourself?
You could say your goal is to make others feel better about themselves than you feel about yourself. While that is honorable, it still won't change that you lack self love. Which means you don't love unconditionally because you don't truly love yourself.