I have found, this thing about "giving a testimony" is more pronounced in certain forms of Christian religious backgrounds, than others. Some people like doing this, some people like giving, hearing, sharing in and supporting a testimony of coming to faith. It is good, nice and helpful for some. Some people have a scripture or two they relate to the practice.
I don't mind talking about my walk/experiences, but I was never influenced by my church to form or practice giving a "testimony" about my godless upbringing, life struggles, choices, seeking God and coming to faith etc.
Well, you take it easy.