The particle accellerato and the timeline confusion

[dragontigerandhorse1985]

From season one, eleven yr old Barry allen had not yet become the Flash because Thawne posing as Harrison Wells had yet to start Star Labs thus the accelerator.

Therefore where did The Flash who had his blood left on the dining room wall come from?

Was it a different earth?

Did Flash go back in time, getting lost there, thus recreating a whole new Flash Point in which eleven yr old Barry stats a new life fully forgetting his pre-timeline self as Flash?

There is not one clue how the Flash who saved young Barry came to be.

any thoughts on this, please?

[Mr. X]

The theory is Flash was always destined to become Flash. What we see is a complete alternate timeline.