Doubling or tripling your strength probably doesn't effectively mean that, anyway.
If anyone can remember say, flat-benching with dumbells, the first time you ever did it, you could probably barely lift the bar, let alone the weights attached to it.
It was not that you were weak, but because it was such an unnatural movement, your supporting motor muscle control was almost absent. After a month of repetition, that control had developed, so now your "big" muscles could apply their full strength.
Having started weights decades ago (stopped now), this is educated guesswork rather than recent, empirical observation. But I reckon (for certain, "unnatural" movements such as the bench press above, a complete newbie could treble their "strength" in 6-8 weeks. The next trebling - 6 months? The next trebling - possibly never.
