Focus on your strengths...

[Gerry Seymour]

Disagree. Some people start with Kickboxing and finish with Systema. Or from Boxing to BJJ. Not many things in common, not the same basics. Yet, same basics all entire martial career may be true for many people.

I think that's picking at semantics. The poster was obviously referring to within a given range of arts (striking arts, for example).

It's not entirely accurate there, though. What I teach students the first few classes is filler material - something they can learn and get some use from quickly. Once they get that, I can start working on the true basics of the art.