I started B1.3, then B1.2 and finally B1.1. But I got those through the A&C routes - a bit simpler in those days.
I have two friends who had/have pilots licences:
1. Was originally an engineer, tried piloting but went back to Eng for the money. Yes, the money.
2. Was originally an Eng became a pilot because he could and then started his own company, doing the check flights himself - because it was cheaper that way and he got the hours in. He doesn't do that now.