Why EA test is forward test better than back test??

Hello, Folks

I had been used EA with $1000 in demo account to process the forward test and back test in September & October. The result as below: *All same EA setting and same broker.
Back test: Balance $1010 (+1%)
Forward test: Balance $1500 (+50%)

I think usually the back test result must better than forward test, because back test is in perfect environment. But forward test is in non-perfect situation such as time delay, slippage, server service broke, & etc..

So, I don't why my forward test is better than back test. Does your testing in forward and back test which is forward test better than back test?? Please kindly advise.

General rule of thumb, backtests are worse especially if you don't have accurate granular data.