It can be done..... the chief pilot at last company was a jeweler by trade... one day he up and sold his business and got all his ratings...instructed for awhile and ended up flying king airs and citations .... 9 years or so later he has 5000 plus hours of flying is the CP and check airman. The CP before him did thirty years at a regular job... and during all those years flew several thousand hours .. upon retirement he started flying corporate and charter full time.. recently retired at 65 with over 16000 hours.... yes it can be done... no it wont be easy.