Or maybe the pilot was aspiring to be a "Red Arrows" display pilot
Contrails are made up of minute ice crystals caused by the freezing of water vapour produced on combustion of a hydrocarbon (avgas). The air would need to be exceedingly cold in order to freeze the water vapour created by combustion. The products of combustion of avgas being in the most part carbon dioxide and water vapour. Realistically the aircraft would need to be above 25,000 ft which is well above the service ceiling of most 172's